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  • 1.
    Aasi, Parisa
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Information Technology Governance: The Role of Organizational Culture and Structure2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Information Technology Governance (ITG) is among the most important challenges for the managers today. IT is not anymore just a supportive tool but also a strategic driver for the businesses. In the dynamic and competitive world of today, it is crucial for organizations to know how to govern IT rather than just to use it. IT governance deals with specifying responsibilities and decision rights to encourage the desirable behaviour from IT and generate value from IT investments. IT governance can impact the overall performance of organizations, however there are still difficulties in understanding IT governance and the factors that may influence it.

    Organizational culture and structure are among the factors that have significant influence on many issues in an organization. According to previous research, organizational culture and structure need to be considered when implementing IT governance. However, there is a lack of research focusing on how organizational culture and structure can influence IT governance performance and implementation. Thus, the main research question addressed in this thesis is: How are organizational culture and structure related to IT governance? To address this question, this research has performed literature reviews and conducted case studies to investigate the role of organizational culture and structure on IT governance. As the first step, the previous literature was reviewed to find the gaps in the research on culture and IT governance. As the next step, four case studies were conducted to explore the influence of organizational culture and structure on IT governance. Two case studies have investigated the relation between organizational structure and IT governance implementation and performance in large organizations; and two other case studies investigated on how different types of organizational culture influence IT governance performance outcomes.

    The results of this research respond to the research question by specifying the role of culture in IT governance through a categorization of prior research both from research and practice perspectives; specifying the influence of different organizational culture types on IT governance performance outcomes in different organizations; and by specifying IT organizational structure relationship with IT governance performance outcomes and IT governance implementation.

    The research presented in this thesis provides both theoretical and empirical contributions to the IT governance research and practice.

  • 2.
    Aasi, Parisa
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Organizational Culture and Structure Influence on Information Technology Governance2016Licentiate thesis, comprehensive summary (Other academic)
  • 3.
    Aggestam, Lena
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    IT-supported Knowledge Repositories: Increasing their Usefulness by Supporting Knowledge Capture2008Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Organizations use various resources to achieve business objectives, and for financial gain. In modern business, knowledge is a critical resource, and organizations cannot afford not to manage it. Knowledge Management (KM) aims to support learning and to create value for the organization. Based on three levels of inquiry (why, what, how), work presented in this thesis includes a synthesized view of the existing body of knowledge concerning KM and hence a holistic characterization of KM. This characterization reveals a strong dependency between KM and Learning Organization (LO). Neither of them can be successful without the other. We show that a KM project resulting in an IT-supported knowledge repository is a suitable way to start when the intention is to initiate KM work. Thus, our research focuses on ITsupported knowledge repositories.

    Large numbers of KM projects fail, and organizations lack support for their KM undertakings. These are the main problems that our research addresses. In order for an IT-supported knowledge repository to be successful, it must be used. Thus, the content of the repository is critical for success. Our work reveals that the process of capturing new knowledge is critical if the knowledge repository is to include relevant and updated knowledge. With the purpose of supporting the capture process, this thesis provides a detailed characterization of the capture process as well as guidance aiming to facilitate the implementation of the capture process in such a way that knowledge is continuously captured, also after the KM implementation project is completed. We argue that the continuous capture of new knowledge which can potentially be stored in the knowledge repository will, in the long term perspective, have a positive influence on the usefulness of the repository. This will most likely increase the number of users of the repository and accordingly increase the number of successful KM projects.

    All the work presented in this thesis is the result of a qualitative research process comprising a literature review and an empirical study that were carried out in parallel. The empirical study is a case study inspired by action research, which involved participation in the project Efficient Knowledge Management and Learning in Knowledge Intensive Organizations (EKLär).

  • 4.
    Aghaee, Naghmeh
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    The Usefulness of ICT Support Systems for Thesis Courses: Learners' Perspectives at Bachelor and Master Level2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Doing a bachelor’s or master’s degree is a journey that leads to success or attrition (dropout). Previous research show to the significance of considering learners’ perspectives and their need for information and different types of interaction. This can be done through online ICTSS (information and communication technology support systems). The overall aim of this dissertation was to create knowledge about how the use of ICTSS can facilitate different types of interaction and support learners in order to reduce thesis problems and attrition and to enhance the quality of the thesis outcomes. The aim was operationalized by two research questions scrutinizing the interaction problems in the thesis process and investigating how the use of ICTSS can facilitate different types of interaction to reduce such problems and attrition, and to enhance the learning opportunities and quality of the thesis outcomes. To answer the research questions, five main studies were performed by applying different research methods on a case study. The empirical studies were performed at the Department of Computer and Systems Sciences (DSV) at Stockholm University, Sweden. The respondents were different learners (students) with active thesis projects at the bachelor or master level in different programs at DSV between 2012 and 2015. For the first two studies, conceptual and content analysis of the data collected from the case study was performed. For the three other studies, open-ended online questionnaires (survey) and interviews were conducted. On the basis of the findings, three main types of interaction issues were developed which related to the need for more learner-content, peer-to-peer, and learner-supervisor interaction in the thesis process. The hypothesis was that the interaction issues could be reduced by implementing a set of strategic suggestions through the use of an ICTSS including a set of functionalities and resources. The usefulness of these functionalities and resources was evaluated with regard to the learners’ perception and experiences. The findings were categorized to facilitate learner-content, peer-to-peer, and learner-supervisor interaction, as well as management of the contents, supervision, and communication of the supervisory team. From these categories, a conceptual framework was developed in this dissertation to illustrate how the use of the ICTSS supports the thesis process. In conclusion, providing access to a set of structured e-resources and supporting educational communication through different types of interaction with peers and the supervisory team, enables learners’ self-managed learning and facilitates similar learning opportunities for learners in thesis courses.

  • 5.
    Aghaee, Naghmeh
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Karunaratne, Thashmee
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Smedberg, Åsa
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Jobe, William Byron
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    ICT for Communication and Collaborative Learning among PhD peers: Results of the Needs and Desires from a PhD Survey2014In: DSV writers hut 2014: proceedings / [ed] Gustaf Juell-Skielse, Stockholm: Department of Computer and Systems Sciences, Stockholm University , 2014, p. 33-40Conference paper (Other academic)
  • 6.
    Aidemark, Jan
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Strategic Planning of Knowledge Management Systems: A Problem Exploration Approach2007Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Knowledge management (KM) is focused on the problems and opportunities of using organizational knowledge as a resource. Information systems that are used to support KM processes are called knowledge management systems (KMS). A KMS is distinguished from any information system by the organizational processes that it supports, that is, creation, capture, storage and dissemination of competences and knowledge. The research area can be summarized as: “Perspectives and frameworks for the strategic planning of knowledge management systems, i.e. information systems for the support of organizational knowledge processes”. We approach the problem area from a strategic point of view, assuming that the problems of the area are based on a socio-technical dimension and that a multiple-paradigm approach is necessary for dealing with the problems of the various KM areas. The research strategy applied to achieve this is interpretative case studies. A number of case studies are used for exploring KM planning areas, developing frameworks for planning and testing the resulting approach. The empirical material consists of three main case studies, together with a number of secondary cases by other writers in the KM field. The outcome of the research is a planning approach, which is given the name: “The problem exploration approach”. The approach is intended for the generation of ideas of possible systems, as a strategic part of knowledge management systems planning. The purpose of the planning approach is to support the creation of a portfolio of KMS. A KMS portfolio is a structured set of information systems that could be developed for an organizational unit. The approach consists of five planning frameworks, all targeting different aspects of an organization. “The problem exploration approach” and its development process are then examined for more general insights into the subject of strategic KM planning. As an outcome of this examination a 12-point program for balancing a planning approach is presented.

  • 7.
    Al Sabbagh, Bilal
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Cybersecurity Incident Response: A Socio-Technical Approach2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis examines the cybersecurity incident response problem using a socio-technical approach. The motivation of this work is the need to bridge the knowledge and practise gap that exists because of the increasing complexity of cybersecurity threats and our limited capability of applying cybersecurity controls necessary to adequately respond to these threats. Throughout this thesis, knowledge from Systems Theory, Soft Systems Methodology and Socio-Technical Systems is applied to examine and document the socio-technical properties of cybersecurity incident response process. The holistic modelling of cybersecurity incident response process developed concepts and methods tested to improve the socio-technical security controls and minimise the existing gap in security controls.

    The scientific enquiry of this thesis is based on pragmatism as the underpinning research philosophy.  The thesis uses a design science research approach and embeds multiple research methods to develop five artefacts (concept, model, method, framework and instantiation) outlined in nine peer-reviewed publications. The instantiated artefact embraces the knowledge developed during this research to provide a prototype for a socio-technical security information and event management system (ST-SIEM) integrated with an open source SIEM tool. The artefact relevance was validated through a panel of cybersecurity experts using a Delphi method. The Delphi method indicated the artefact can improve the efficacy of handling cybersecurity incidents.

  • 8.
    Alwazae, Meshari
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Template-driven Documentation of Best Practices2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Knowledge Management has become a key instrument for identifying, creating and sharing organizational knowledge assets. An attractive means for sharing knowledge is Best Practices (BPs), which are proven as well as efficient and effective solutions to recurring problems. BPs can offer significant benefits, including improved performance, reduced re-work and cost savings. However, it is challenging to share and use BP Documents (BPDs) in organizations, which is the overall problem addressed in this thesis. More precisely, the thesis focuses on two sub-problems: 1) The difficulty of finding and selecting appropriate BPs in large collections of BPs impedes the use of BPs, and 2) The low quality of BPDs impedes the use of BPs. Related to these problems, the thesis addresses two sub-goals. The first one is to design a BP Annotation Template for supporting the identification and selection of BPs in BP repositories. The template can be used for organizing and indexing the contents of BPDs independent of domain. The second sub-goal is to design a BP Document Template for supporting the creation, use and evaluation of BP documentation. The BP Document Template offers a structure for describing BPs in a detailed and systematic way.

     

    The research methodology applied is design science, which is the scientific study and creation of artifacts as they are developed and used by people with the goal of solving practical problems. The first artifact, the BP Annotation Template, has been designed and developed based on a literature study and evaluated using expert interviews. The second artifact, the BP Document Template, has been designed and developed based on a literature study using grounded theory as well as on interviews with KM experts. The BP Document Template has been evaluated using expert interviews and demonstrated by being applied in three real-life cases. By basing the two artifacts on literature studies, the two artifacts consolidate, integrate and extend previous work on BP documentation.

     

    The evaluations indicate that the BP Annotation Template provides a strong foundation for identifying and selecting BPs, independent of domain, and that the BP Document Template can support the structuring of BP documents so that they become complete, uniform and easy-to-use. An identified drawback of the two artifacts is the need for extensive resources for implementing and applying them since they may be complex and time-consuming to use. The artifacts are expected to support BP designers as well as BP managers and BP users.

  • 9.
    Andrenucci, Andrea
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Using Language Technology to Mediate Medical Information on Health Portals: User Studies and Experiments2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The World Wide Web has revolutionized our lifestyle, our economies and services within health care. Health care services are no longer provided only at specialist centers and at scheduled hours, but also through online tools that give health care consumers access to medical information, health records, medical counselling and peer support. Such tools and applications are generally available on larger web sites or gateways called health portals. A large majority of online medical information consumers are laypeople (i.e. non experts) who appreciate the possibility to submit their information needs in their own native language. The information retrieval process where information requests from users and retrieved documents/answers are in different languages is called cross-language information retrieval (CLIR). 

    Mental health is one of the medical areas where some online applications have been successfully deployed in order to help people by providing in-depth medical information, counseling and advice. Despite the fact that online health portals are considered priority e-health tools for improving mental health, there are no formal knowledge instruments such as knowledge patterns that explicitly support the development of online health portals in the field of psychology/psychotherapy. 

    The goal of this research is to produce and evaluate a set of knowledge patterns, for the development and implementation of cross-lingual online health portals aimed at information seekers without medical expertise in the domain of psychology and psychotherapy. The knowledge patterns synthetize results of three research foundations: 1) User studies of portal interaction, based on interviews and observations about how users experience health information online and personalized search 2) Knowledge integration of existing language technology approaches, and 3) Experiments with language technology applications, in the field of cross-lingual information retrieval/question-answering. The target groups of this research are developers, researchers and health care providers, i.e. people who are responsible for mediating medical information on online health portals for users without medical expertise. 

    The chosen research framework is design science, i.e. the science that focuses on the study, development and evaluation of artefacts (objects that help people solve a practical problem). Typical examples of artefacts in IT are algorithms, software solutions and databases, but also objects such as processes or knowledge patterns. The developed and evaluated artefact in this research is a set of knowledge patterns for online health portal development. 

    The developed artefact contains fourteen knowledge patterns covering the three research foundations. Formative (structured workshops) and summative (online survey) evaluation of the artefact indicate that the knowledge patterns are useful, relevant and adoptable to a large extent, they also provide further directions for development of online mental health portals. Developing portals with multilingual support and tailored interfaces has the potential of helping larger groups of citizens to access relevant medical information.

  • 10.
    Argaw, Atelach Alemu
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Resource Lenient Approaches to Cross Language Information Retrieval: Using Amharic2011Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Information Retrieval (IR) deals with finding and presenting information from a collection of documents/data that are relevant to an information need (a query) expressed by a user. Cross Language Information Retrieval (CLIR) is a subfield of IR where queries are posed in a different language than that of the document collection. Computational linguistic tools and resources are essential to accomplish the tasks in CLIR and to date, CLIR research is dominated by a very limited number of languages for which such tools and resources are available. In order to facilitate global information sharing, it is important to enable access to information using as many languages as possible. This requires an investigation into the feasibility of CLIR for languages with a limited set of computational linguistic resources.

    Amharic is a well-studied language with a rich history and culture, but has very limited computational linguistic tools and resources. This dissertation provides an in depth investigation into a CLIR system for Amharic (against English and French document collections). Scalable techniques were developed to accomplish Amharic CLIR tasks and each task was evaluated individually as a stand alone experiment. Large scale IR experiments were then conducted in order to evaluate the effect of three parameters, namely, transliteration, word sense discrimination, and term selection based on part of speech tags, on the overall IR performance. The effects were measured by individually tuning each of these parameters through a series of benchmarking experiments, geared towards optimizing retrieval precision as well as recall. The results give an insight into the performance of the chosen approaches, the challenges, and their impact on the overall IR performance.

  • 11.
    Asker, Lars
    Stockholm University, Faculty of Social Sciences.
    Partial explanations as a basis for learning1994Doctoral thesis, monograph (Other academic)
  • 12.
    Back, Jon
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Designing Activity and Creating Experience: On People’s Play in Public places2013Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis deals with the design of play in public places; this can mean both pervasive games and other freer play activities. In these activities (as well as in many other game activities) the same game can spur many different ways to play it, and the same activity can be experienced differently by different players, and even differently on different occasions for the same player. An activity such as playing must be observed as a whole. The surrounding cul- ture, player preconceptions and the emergent mood within the group will affect the experience.

    By analysing previous frameworks, and using own design examples, a three level design framework is developed, functioning as a lens towards understanding the design of playful activities. The framework focuses on the player perspective, offering game design as an invitation and encouragement to engage in certain activities. The framework distinguishes between design at three levels:

    1. Designed construct (e.g. artefacts and rules)
    2. Activity
    3. Experiences

    But it remains to be understood why people engage in the activities that lead to playful experiences. What encourages playful engagement? And why do people want to play one game, and not another?

    This question can be split into two parts:

    • Engagement: starting to be interested in the activity
    • Commitment: actually caring for the experience

    This issue is identified in the thesis, and examples show how convoluted this problem is, in particular in pervasive game settings. Challenges are pre- sented for future work.

  • 13.
    Backlund, Per
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Development Process Knowledge Transfer through Method Adaptation, Implementation, and Use2004Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Information Systems Engineering (ISE) is an interdisciplinary approach to enable the realisation of successful information systems in a broad sense. ISE comprises a number of areas of expertise that must be integrated and managed in order to build information systems. Since ISE is becoming progressively more complex there is an increasing need to codify and manage knowledge within and about the ISE process.

    From a knowledge perspective the different model types created in an ISE project are examples of codified knowledge about the future system. The descriptions of how work should proceed are examples of codified knowledge of the process of creating the system. In summary, one of the main concerns in the ISE process is to manage the substantial amount of knowledge associated with the process as such as well as with the target domain of the actual development project and the developed software.

    In the thesis I recognise three areas of knowledge in ISE: development process knowledge, target domain knowledge, and software knowledge. Furthermore, I use a set of knowledge perspectives in order to describe and analyse ISE from a knowledge perspective. Finally, I introduce three aspects: organisation, artefact, and individual in order to be able to discuss and analyse how methods are actually used in organisations and how they affect the work situation.

    The results are presented in the form of a framework for knowledge transfer in ISE that comprises the knowledge perspective, the knowledge area, and the aspect of knowledge transfer. The framework is thus used to analyse the results from the six papers enclosed in the thesis. The results also comprise an empirical characterisation of a method in use which is based on data collected during an ethnographical study. Finally the results are made concrete in the form of a pattern collection for method introduction and method use.

  • 14.
    Bahati, Bernard
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Technology-enhanced formative assessment in higher education: An intervention design of scaffolding student self-regulated learning2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    As online learning is increasingly adopted in higher education institutions, many instructors are faced with the challenges of devising and implementing effective pedagogical practices that advance student learning. One of the challenges points to the design and development of assessment activities that truly inform the teaching and learning process. Despite the fact that both formative and summative assessment are important in teaching and learning, summative assessment has been dominating instructional processes in higher education at the expense of formative assessment. In higher education, in many countries including Rwanda, efforts that are made to practice formative assessment are hampered by a variety of factors that lead to ill-practices. Using technology-enhanced instructional interventions, this study attempted to address these factors. The study aimed at developing technology-enhanced instructional interventions to support student-based formative assessment that promote self-regulated learning. Additionally, this study proposes the design guidelines for the development of such instructional interventions. The study was guided by the following general research question: What are the characteristics of technology-enhanced formative assessment activities that promote student self-regulated learning? This research question was addressed using three specific research questions: (1) How do lecturers and students understand and practice formative assessment and feedback? (2) How can technology-enhanced formative assessment activities help student develop self-regulated learning skills? (3) What design guidelines should be followed in order to develop technology-enhanced formative assessment activities that promote student self-regulated learning? This study used Educational Design Research approach. Technology-enhanced instructional interventions were formatively developed, iteratively tested and evaluated in order to help students develop their self-regulated learning skills. Based on the findings of this study, three improved formative e-assessment packages are proposed as a practical research contribution: online knowledge survey, online peer-scaffolding through student-generated questions and peer-responses, and electronic reflective journals. In addition, based on the findings, this dissertation suggests a set of design guidelines and lessons learned in order to inform other educational practitioners who would like to develop technology-enhanced formative assessment activities that promote student-regulated learning.

  • 15.
    Bakari, Jabiri Kuwe
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    A Holistic Approach for Managing ICT Security in Non-Commercial Organisations: A Case Study in a Developing Country2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The research reported here is about improvement of the ICT security management process in non-commercial organisations in order to reduce possible financial damage, taking into consideration the realities found in developing countries. The research took place in a developing country—Tanzania, where five organisations were involved.

    The study is organised into seven papers covering: the state of ICT security management in the organisations; prerequisites when utilising the existing ICT security management approaches in attaining a solution for managing ICT security in the organisations; issues and challenges of managing ICT security; important aspects to be taken into consideration in order to successfully manage ICT security; and how the management of ICT security in non-commercial organisations could be improved. Among others, the research was motivated by the observed need for bridging the perception gap between the management and technicians when dealing with the ICT security problem, and consequently extending to a common understanding by the staff in the various departments and specialities within and between the departments.

    The thesis contributes to increased empirical knowledge on the importance of the holistic ICT security management process. Particularly, our main contribution is the proposed holistic approach for managing ICT security in non-commercial organisations, organised in the form of guidelines with two main phases: the initialisation phase which involved the introduction of the ICT security management process in the organisation; and the internalised and continuous phase.

  • 16.
    Basher, Mohammad Ariful
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Roy, Palash Chandra
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Introducing an e-Health Card for Developing Countries: A Case Study of Bangladesh2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 17.
    Bergholtz, Maria
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Ekenberg, Love
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Hansson, Karin
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Johannesson, Paul
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Snygg, Joakim
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Framework for evaluating tools used in edemocracy: transparency, autonomy, consensus and pluralism2014In: DSV writers hut 2014: proceedings, Stockholm: Department of Computer and Systems Sciences, Stockholm University , 2014Conference paper (Other academic)
    Abstract [en]

    The concept of e-democracy has been around for a while. However, the intercontextual understanding of this is still immature which complicates interdisciplinarity and communication with a diversity of stakeholders, resulting in a weak participation and implementation of e-services. This is even more emphasized in an international setting, not the least in the context of various European Union initiatives regarding e-service provision. To increase the participation in the context, e-democracy services can be utilized for strengthening individual capabilities as well as political processes. The effective design of such processes requires tools to support decision-making, collaboration, and collaborative decision-making, voting engagement and involvement in the democratic process. This article presents an evaluation framework suitable for tools for e-democracy aiming at forming a constructive base for implementing an efficient support for enabling an increased participation in vital democratic processes.

  • 18.
    Björck, Fredrik
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Discovering Information Security Management2005Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis is concerned with issues relating to the management of information security in organisations, motivated by the need for cost-efficient information security.

    It is based on the assumption that: in order to achieve cost-efficient information security, the point of departure must be knowledge about the empirical reality in which the management of information security takes place.

    The data gathering instruments employed are questionnaires with open-ended questions and unstructured research interviews. The empirical material is analysed, and conclusions are drawn following the principles of Grounded Theory. Data sources are professionals in the area of information security management, including information security consultants (n=13), certification auditors (n=8), and information security managers (n=8).

    The main contributions are: an integrated model illustrating the experts’ perceptions concerning the objectives, actors, resources, threats, and countermeasures of information security management; a framework for the evaluation, formation, and implementation of information security management systems; a new approach for the evaluation of information security in organisations; a set of success factors concerning the formation of information security management systems; and a problem inventory concerning the value and assessment of information security education and training.

  • 19.
    Brash, Danny
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Reuse in information systems development: a qualitative inquiry2002Doctoral thesis, monograph (Other academic)
  • 20.
    Britts, Stefan
    Stockholm University, Faculty of Social Sciences.
    Object database design1994Doctoral thesis, monograph (Other academic)
  • 21.
    Brouwers, Lisa
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Microsimulation Models for Disaster Policy Making2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Two executable simulation models for answering policy questions were designed and implemented. The first for a flood management case, and the second for a disease transmission case that is currently underway. The flood simulation model differs from earlier natural disaster simulation models in several respects. It represents explicitly the geographical location and the economic strength of each household. It is also equipped with a graphical user interface, making it possible to design policies interactively, and to test their outcomes. If policy options are compared, the simulation results can automatically be transformed into decision trees. The flood simulation model shows that a micro-level representation makes it possible to investigate the distributional effects of policy changes. Novel features of the disease transmission model include the use of (anonymized) data representing nine million individuals, the inclusion of important parts of the contact patterns, and the explicit representation of places. The disease transmission model shows that the incorporation of social structure allows for a more realistic representation of disease spread than do models that assume homogenous mixing. Using this model, it is possible to conduct experiments of significant policy relevance, such as investigating the initial growth of an epidemic on a real-world network. Together, the two cases demonstrate the usefulness of a spatially explicit micro-level representation for policy simulation models in the area of disaster management.

  • 22.
    Byungura, Jean Claude
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Improving IT Integration for Higher Education Institutional Performance: Towards a Contextualised IT-Institutional Alignment Model2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The integration of information technology (IT) into service delivery is currently seen as an innovative strategy to support the modernising of universities worldwide. However, in some institutions in developing countries, including Rwanda, IT has failed to add the intended value to university services, despite huge associated investments in IT. Consequently, IT-organisational alignment continues to be a primary concern for university managers. This alignment is viewed in terms of its strategic, socio-cultural, and technological dimensions. For effective IT-institutional alignment, several antecedents (alignment practices) for creating an appropriate fit between IT and organisations have been suggested in the literature. However, several studies exploring IT alignment focused mainly on general business companies, and similar research with an emphasis on higher education institutions is still scarce. Therefore, the aim of this research was twofold: firstly, it attempted to understand the process of IT integration into universities; and secondly, to propose a contextual model for IT-institutional alignment within a higher education context. A design science research methodology (DSRM) was applied in this research, using surveys and case studies as research strategies. Preliminary findings at the exploration phase of this research indicated a strong misalignment between IT and the university services caused by the lack of clearly defined alignment practices. Furthermore, as the research main outcome, an IT-Institutional Alignment Model (ITIAM) was proposed after reaching an understanding of the current state and challenges related to IT integration into teaching, learning, research and university administration. This model includes 44 alignment practices, related to both technical and non-technical dimensions. These alignment practices were clustered under six categories: (1) Communication, (2) Structure/Governance, (3) Technology Scope, (4) Competence/Value Measurement, (5) Skills, and (6) Partnership. Alignment practices related to institutional structure and governance, skills and communication were found to have a strong positive influence on the institutional performance, as compared to those related to competence and value measurement, partnership, and technology scope. Based on the research findings, the proposed ITIAM, which was iteratively tested and evaluated using case study institutions, was found to be a relevant tool for guiding the implementation of IT systems towards the improvement of institutional performance. Hence, this thesis makes a theoretical contribution by applying the concept of IT alignment within a higher education context and by documenting the empirically tested contextual alignment practices as conveyed in the ITIAM Model. Additionally, as a practical implication, the results can serve as a reference for an effective IT integration process in university services and for how to improve performance through effective use of IT in teaching, learning, research and educational management.

  • 23.
    Cakici, Baki
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    The Informed Gaze: On the Implications of ICT-Based Surveillance2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Information and communication technologies are not value-neutral. I examine two domains, public health surveillance and sustainability, in five papers covering: (i) the design and development of a software package for computer-assisted outbreak detection; (ii) a workflow for using simulation models to provide policy advice and a list of challenges for its practice; (iii) an analysis of design documents from three smart home projects presenting intersecting visions of sustainability; (iv) an analysis of EU-financed projects dealing with sustainability and ICT; (v) an analysis of the consequences of design choices when creating surveillance technologies. My contributions include three empirical studies of surveillance discourses where I identify the forms of action that are privileged and the values that are embedded into them. In these discourses, the presence of ICT entails increased surveillance, privileging technological expertise, and prioritising centralised forms of knowledge.

  • 24.
    Casmir, Respickius
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    A Dynamic and Adaptive Information Security Awareness (DAISA) Approach2005Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Information systems fail not only because of problems with technology used and technical incompetence of professionals administering them but also because of lack of security awareness to the end users. In addition, various research results have revealed that security and reliability of IS/IT systems is a function of technology, processes and people.

    This research has focused on the latter aiming at developing an integrated information security education, training and awareness learning continuum. Particularly, the research has focused on developing countries where a little has been done to address information security learning continuum. The research has been done in two cyclic phases in which cycle one has chiefly addressed security education and training aspects whereas cycle two has mainly focused on security awareness aspects. Based on empirical analysis of security practices in organisations; the thesis proposes a Dynamic and Adaptive Information Security Awareness (DAISA) approach. Founded on six interdependent pillars, the approach delineates high level guidelines for establishing and maintaining information security awareness programs at workplaces.

  • 25.
    Caster, Ola
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Quantitative methods to support drug benefit-risk assessment2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Joint evaluation of drugs’ beneficial and adverse effects is required in many situations, in particular to inform decisions on initial or sustained marketing of drugs, or to guide the treatment of individual patients. This synthesis, known as benefit-risk assessment, is without doubt important: timely decisions supported by transparent and sound assessments can reduce mortality and morbidity in potentially large groups of patients. At the same time, it can be hugely complex: drug effects are generally disparate in nature and likelihood, and the information that needs to be processed is diverse, uncertain, deficient, or even unavailable. Hence there is a clear need for methods that can reliably and efficiently support the benefit-risk assessment process. For already marketed drugs, this process often starts with the detection of previously unknown risks that are subsequently integrated with all other relevant information for joint analysis.

    In this thesis, quantitative methods are devised to support different aspects of drug benefit-risk assessment, and the practical usefulness of these methods is demonstrated in clinically relevant case studies. Shrinkage regression is adapted and implemented for large-scale screening in collections of individual case reports, leading to the discovery of a link between methylprednisolone and hepatotoxicity. This adverse effect is then considered as part of a complete benefit-risk assessment of methylpredniso­lone in multiple sclerosis relapses, set in a general framework of probabilistic decision analysis. Two methods devised in the thesis substantively contribute to this assessment: one for efficient generation of utility distributions for the considered clinical outcomes, driven by modelling of qualitative information; and one for computing risk limits for rare and otherwise non-quantifiable adverse effects, based on collections of individual case reports.

  • 26.
    Chaula, Job Asheri
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    A Socio-technical Analysis of Information Systems Security Assurance: A Case Study for Effective Assurance2006Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis examines the concepts of Information System (IS) security assurance using a socio-technical framework. IS security assurance deals with the problem of estimating how well a particular security system will function efficiently and effectively in a specific operational environment. In such environments, the IS interact with other systems such as ethical, legal, operational and administrative. Security failure in any of these systems may result in security failure of the whole system.

    In this thesis a socio-technical framework is used to examine culture, usability problems, security internal controls, security requirements and re-use of security requirements of TANESCO information systems. TANESCO is the energy utility company in Tanzania where the case study was conducted. Results show that culture affects the way people approach IS security. Also results show that the socio-technical framework is effective in modeling systems security and its environment. The re-use of security requirements is also shown to significantly minimise the time taken when developing and improving security requirements for an IS.

    The overall purpose of this thesis has been to develop a framework for information systems security assurance. The resulting framework of thinking brings together numerous assurance concepts into a coherent explanation that should be useful for any organisation or evaluators seeking to understand the underlying principals of systems security assurance. It contains organisational, cultural, and technical issues that should be looked at when considering and applying systems security assurance methods and techniques.

  • 27.
    Chemane, Lourino
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    ICT Platform Integration - MCDM Based Framework for the Establishment of Value Network: Case Study: Mozambique Government Electronic Network (GovNet)2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The selection of ICT service providers are among many of the challenges in building networks (intranets and extensions to the Internet) due to the high investment on equipment (CAPEX) and on operational costs (OPEX). This thesis proposes a Multi-Criteria Decision Method based decision support framework via the deployment of the Analytical Hierarchy Process method that can be used to improve selection and evaluation practices. The work deals explicitly with the role of ICT in supporting the corporate mission, and goals, in building the organization value network. It helps also in planning and defining the access to the Internet and strategies for making critical ICT related decisions. A specific study, The Government Electronic Network Project in Mozambique, has been used as a use case for the developed model and for validating the framework. The thesis also covers aspects related to the broader eGovernment process in Mozambique, such as the architecture, the principles, and the associated IT protocols and standards required for the interoperability of the respective eGovernment systems.

    The framework and recommendations are expected to contribute in assisting organizations to increase the usage and improve the management of IT platforms and services. In addition, they should help in bettering the systematization of the input data in specifying the requirements for the services offered by Internet service providers. The model should bring to the attention of decision-makers many factors that are currently neither considered nor are central to the selection processes. Furthermore, the decision-makers can use the framework in explaining and describing the investment decisions behind ICT projects in the context of the organization value network.

  • 28.
    Cöster, Rickard
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Algorithms and Representations for Personalised Information Access2005Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Personalised information access systems use historical feedback data, such as implicit and explicit ratings for textual documents and other items, to better locate the right or relevant information for individual users.

    Three topics in personalised information access are addressed: learning from relevance feedback and document categorisation by the use of concept-based text representations, the need for scalable and accurate algorithms for collaborative filtering, and the integration of textual and collaborative information access.

    Two concept-based representations are investigated that both map a sparse high-dimensional term space to a dense concept space. For learning from relevance feedback, it is found that the representation combined with the proposed learning algorithm can improve the results of novel queries, when queries are more elaborate than a few terms. For document categorisation, the representation is found useful as a complement to a traditional word-based one.

    For collaborative filtering, two algorithms are proposed: the first for the case where there are a large number of users and items, and the second for use in a mobile device. It is demonstrated that memory-based collaborative filtering can be more efficiently implemented using inverted files, with equal or better accuracy, and that there is little reason to use the traditional in-memory vector approach when the data is sparse. An empirical evaluation of the algorithm for collaborative filtering on mobile devices show that it can generate accurate predictions at a high speed using a small amount of resources.

    For integration, a system architecture is proposed where various combinations of content-based and collaborative filtering can be implemented. The architecture is general in the sense that it provides an abstract representation of documents and user profiles, and provides a mechanism for incorporating new retrieval and filtering algorithms at any time.

    In conclusion this thesis demonstrates that information access systems can be personalised using scalable and accurate algorithms and representations for the increased benefit of the user.

  • 29.
    Dayarathna, Rasika
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Discovering Constructs and Dimensions for Information Privacy Metrics2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Privacy is a fundamental human right. During the last decades, in the information age, information privacy has become one of the most essential aspects of privacy. Information privacy is concerned with protecting personal information pertaining to individuals.

    Organizations, which frequently process the personal information, and individuals, who are the subjects of the information, have different needs, rights and obligations. Organizations need to utilize personal information as a basis to develop tailored services and products to their customers in order to gain advantage over their competitors. Individuals need assurance from the organizations that their personal information is not changed, disclosed, deleted or misused in any other way. Without this guarantee from the organizations, individuals will be more unwilling to share their personal information.

    Information privacy metrics is a set of parameters used for the quantitative assessment and benchmark of an organization’s measures to protect personal information. These metrics can be used by organizations to demonstrate, and by individuals to evaluate, the type and level of protection given to personal information. Currently, there are no systematically developed, established or widely used information privacy metrics. Hence, the purpose of this study is to establish a solid foundation for building information privacy metrics by discovering some of the most critical constructs and dimensions of these metrics. 

    The research was conducted within the general research strategy of design science and by applying research methods such as data collection and analysis informed by grounded theory as well as surveys using interviews and questionnaires in Sweden and in Sri Lanka. The result is a conceptual model for information privacy metrics including its basic foundation; the constructs and dimensions of the metrics. 

  • 30.
    Dudas, Catarina
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences. University of Skövde.
    Learning from Multi-Objective Optimization of Production Systems: A method for analyzing solution sets from multi-objective optimization2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The process of multi-objective optimization involves finding optimal solutions to several objective functions. However, these are typically in conflict with each other in many real-world problems, such as production system design. Advanced post-optimization analysis can be used to provide the decision maker with information about the underlying system. The analysis can be based on the combination of simulation-based multi-objective optimization and learning from the obtained solution set. The goal of the analysis is to gain a deeper understanding of the problem at hand, to systematically explore and evaluate different alternatives, and to generate essential information and knowledge to support the decision maker to make more informed decisions in order to optimize the performance of the production system as a whole.

    The aim of this work is to explore the possibilities on how post-optimization analysis can be used in order to provide the decision maker with essential information about an underlying system and in what way this information can be presented. The analysis is mainly done on production system development problems, but may also be transferred to other application areas.

    The research process of the thesis has been iterative, and the initial approach for post-optimization analysis has been refined several times. The distance-based approach developed in the thesis is used to allow the extraction of information about the characteristics close to a user-defined reference point. The extracted rules are presented to the decision maker both visually, by mapping the rules to the objective space, and textually. The method has been applied to several industrial cases for proof-by-demonstration as well as to an artificial case with information known beforehand to verify the distance-based approach, and the extracted rules have also been used to limit the search space in the optimization. The major finding in the thesis is that to learn from optimization solution sets of production system problems with stochastic behavior, a distance-based approach is advantageous compared with a binary classification of optimal vs. non-optimal solutions.

  • 31.
    Edirisuriya, Ananda
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Design Support for e-Commerce Information Systems using Goal, Business and Process Modelling  2009Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Enterprises use various models to find design solutions to their e-Commerce information systems. Goal, business and process models are parts of a chain of models used for this purpose. Business modelling requires structured methods to support design and traceability. Process modelling also needs structured methods to manage design complexity, traceability and flexibility. The thesis proposes several artifacts to address these challenges.

     It proposes a method to design business models from goal models. We start by analyzing strategic goals and express goal model notions using business notions. A set of guidelines is proposed to design a business model. The method provides structured business model design and traceability of the decisions from business to strategic level.

    The thesis also discusses a set of mappings to relate goal modelling language constructs to process modelling notions. We use BMM, i* and KAOS for goal modelling. The mappings are used to identify how these techniques can support process design. In addition, a set of mappings is proposed to relate business modelling language constructs to process modelling notions. We use the e3value model for business modelling. Based on these mappings a number of activities are identified to structure process activities from a business viewpoint.

    We also propose a method to design process models using goal and business models as inputs. As a bridge between two input models and a process model, the notion of an activity dependency model is introduced. The transitions between models are performed by using guidelines. The method provides structured process model design, flexibility for process models and traceability of the decisions from operational to strategic and business levels.

    These artifacts can be used for designing enterprise business and process models. We follow the design science research method used in information systems research. The evaluation builds on scenarios, implementations and a literature review.

  • 32.
    Ehrentraut, Claudia
    et al.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Ibrahim, Osama
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Dalianis, Hercules
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Text Analysis to support structuring and modelling a public policy problem: Outline of an algorithm to extract inferences from textual data2014In: DSV writers hut 2014: proceedings / [ed] Gustaf Juell-Skielse, Stockholm: Department of Computer and Systems Sciences, Stockholm University , 2014Conference paper (Other academic)
    Abstract [en]

    Policy making situations are real-world problems that exhibit complexity in that they are composed of many interrelated problems and issues. To be effective, policies must holistically address the complexity of the situation rather than propose solutions to single problems. Formulating and understanding the situation and its complex dynamics, therefore, is a key to finding holistic solutions. Analysis of text based information on the policy problem, using Natural Language Processing (NLP) and Text analysis techniques, can support modelling of public policy problem situations in a more objective way based on domain experts’ knowledge and scientific evidence. The objective behind this study is to support modelling of public policy problem situations, using text analysis of verbal descriptions of the problem. We propose a formal methodology for analysis of qualitative data from multiple information sources on a policy problem to construct a causal diagram of the problem. The analysis process aims at identifying key variables, linking them by cause-effect relationships and mapping that structure into a graphical representation that is adequate for designing action alternatives, i.e., policy options. This study describes the outline of an algorithm used to automate the initial step of a larger methodological approach, which is so far done manually. In this initial step, inferences about key variables and their interrelationships are extracted from textual data to support a better problem structuring. A small prototype for this step is also presented.

  • 33.
    Ekanayake, Hiran B.
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences. University of Colombo School of Computing.
    Validating User Engagement and Effectiveness of Training Simulations: A mixed-methods approach informed by embodied cognition and psychophysiological measures2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Simulation-based training has gained widespread attention recently as a response to drawbacks associated with traditional training approaches, such as high training costs (instructors, equipment, etc.), high risks (e.g. pilot training), and ethical issues (e.g. medical training), as well as a lack of availability of certain training environments (e.g. space exploration). Apart from their target training domains, many of aspects of simulations differ, such as their degree of physical realism (fidelity), scenarios (e.g. story), and pedagogical aspects (e.g. after-action reviews and collaborative learning). Among those aspects, designers have mostly focused on developing high-fidelity simulations with the expectation of increasing the effectiveness of training. However, some authors suggest that the above belief is a myth as researchers have failed to identify a linear relationship between the (physical) fidelity and training effectiveness of simulations.  Most researchers have therefore evaluated the correspondence between the behaviours of trainees in both real world and simulated contexts, however, the existing methods of simulation validation using behavioural measures have a number of drawbacks, such as the fact that they do not address certain complex phenomena of skills acquisition.

    Bridging the above knowledge gap, this research reports on empirical investigations using an improved methodology for validating training simulations. This research includes an investigation of the user experience of trainees, with respect to the acceptance of virtual scenarios provoking a similar psychophysiological response as in real world scenarios, and the training potential of simulations with respect to the positive transfer of training from a simulator to real world operational contexts. The most prominent features of the proposed methodology include the use of psychophysiological measures in addition to traditional behavioural measures and the use of natural (quasi-) experiments. Moreover, its conceptual framework was influenced by contemporary theories in cognitive science (e.g. constructivism and embodied cognition). The results of this research have several important theoretical and methodological implications, involving, for example, the dependency of the effectiveness of simulations on the perceived realism of trainees, which is more embodied than has been predicted by previous researchers, and the requirement of several different types/levels of adaptive training experience, depending on the type of trainee.

  • 34.
    Ekenberg, Love
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Decision support in numerically imprecise domains1994Doctoral thesis, monograph (Other academic)
  • 35.
    Elias, Mturi
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Design of Business Process Model Repositories: Requirements, Semantic Annotation Model and Relationship Meta-model 2015Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Business process management is fast becoming one of the most important approaches for designing contemporary organizations and information systems. A critical component of business process management is business process modelling. It is widely accepted that modelling of business processes from scratch is a complex, time-consuming and error-prone task. However the efforts made to model these processes are seldom reused beyond their original purpose. Reuse of business process models has the potential to overcome the challenges of modelling business processes from scratch. Process model repositories, properly populated, are certainly a step toward supporting reuse of process models.

    This thesis starts with the observation that the existing process model repositories for supporting process model reuse suffer from several shortcomings that affect their usability in practice. Firstly, most of the existing repositories are proprietary, therefore they can only be enhanced or extended with new models by the owners of the repositories. Secondly, it is difficult to locate and retrieve relevant process models from a large collection. Thirdly, process models are not goal related, thereby making it difficult to gain an understanding of the business goals that are realized by a certain model. Finally, process model repositories lack a clear mechanism to identify and define the relationship between business processes and as a result it is difficult to identify related processes.

    Following a design science research paradigm, this thesis proposes an open and language-independent process model repository with an efficient retrieval system to support process model reuse. The proposed repository is grounded on four original and interrelated contributions: (1) a set of requirements that a process model repository should possess to increase the probability of process model reuse; (2) a context-based process semantic annotation model for semantically annotating process models to facilitate effective retrieval of process models; (3) a business process relationship meta-model for identifying and defining the relationship of process models in the repository; and (4) architecture of a process model repository for process model reuse.

    The models and architecture produced in this thesis were evaluated to test their utility, quality and efficacy. The semantic annotation model was evaluated through two empirical studies using controlled experiments. The conclusion drawn from the two studies is that the annotation model improves searching, navigation and understanding of process models. The process relationship meta-model was evaluated using an informed argument to determine the extent to which it meets the established requirements. The results of the analysis revealed that the meta-model meets the established requirements. Also the analysis of the architecture against the requirements indicates that the architecture meets the established requirements.

  • 36.
    Eliasson, Johan
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Tools for Designing Mobile Interaction with the Physical Environment in Outdoor Lessons2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Mobile technologies are increasingly being used to support students in outdoor learning activities. For instance, in a growing number of research projects, smartphones and positioning technologies are being used to support students in exploring the natural environment. However, previous research has identified challenges with the introduction of mobile technology into outdoor lessons. One fundamental challenge is that interaction with mobile technology in outdoor lessons may distract students from interacting with the physical environment. In this thesis this challenge is approached from the perspective of human-computer interaction, guided by the following research question: How can we design, evaluate, and reflect on mobile technology for interacting with the physical environment in outdoor lessons? The thesis presents four design cases on outdoor geometry and biology lessons, which act as probes for developing conceptual design tools. The design cases were developed through a concept-driven design approach and evaluated on field tests with primary school students. Future workshop and Interaction analysis were the main methods used. The results of the field tests suggest that mobile technology needs to be designed to orientate students in their interaction with the physical environment. In line with the concept-driven design approach, the thesis proposes three design tools. The design tools proposed are: Design guidelines that are specific enough for guiding the design of mobile technology for outdoor lessons, a Design model for designing and evaluating mobile technology for outdoor lessons, and Design concepts for reflecting on the placement of mobile technology in outdoor lessons. The design tools are proposed as tools for researchers and designers to take the challenge of distraction into account in designing mobile technology for outdoor lessons.

  • 37.
    El-Mekawy, Mohamed Sobaih
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    FROM SOCIETAL TO ORGANISATIONAL CULTURE: THE IMPACT ON BUSINESS-IT ALIGNMENT2012Licentiate thesis, monograph (Other academic)
    Abstract [en]

    Business-IT alignment (BITA) has clearly become more important over the last decade. However, considerable difficulties remain when attempting to achieve a mature level of BITA. Therefore, research efforts which have resulted in a number of theoretical models have been able to help in devising and applying supportive tools for assessing different components of BITA. However, most of these efforts have either been produced in Anglo-Saxon countries or have been based on specific experiences in those countries. Consequently, they have tended to ignore a number of factors which differ in nature due to variations in cultural contexts. However, organisational culture has been given little consideration. Societal and organisational cultural aspects of BITA are particularly important because the majority of BITA models tend to focus more on the efficiency and effectiveness of BITA components rather than on trying to create ways in which how BITA can be achieved or maintained in different contexts. Therefore, the purpose of this thesis is to investigate the impact of societal and organisational culture on achieving BITA and influencing its maturity. The main result is an extended BITA model developed originally by Luftman, known as; Luftman’s Strategic Alignment Maturity Model (SAM), which is influenced by the organisational culture perspective. The research method and process advocated by Peffers et al. (2007) is used in the thesis to design the extended-SAM, consisting of six activities. The first of these activities involves identifying specific problems. This is achieved by an extensive literature survey of theories related to BITA, an explorative study of the impact of organisational culture on BITA and a classification of the general limitations of BITA. The second activity concerns the requirement for definitions of the designed artifact. The third activity is then specified in terms of designing the artifact; i.e. an extended-SAM. The design is based on constructed hypotheses of the potential impact of organisational culture elements (based on Smit et al.’s model (2008) on BITA attributes (based on SAM), and followed by an empirical study of 6 multinational organisations, for testing the hypotheses. Following that, in the fourth activity, various processes for extending SAM are demonstrated in different seminars within the IT management group at DSV, in conference papers and in different seminars of the Swedish research School of Management and Information Technology (MIT) (Forskarskolan Management och IT. In the fifth activity, the extended-SAM model is evaluated in 5 multinational organisations to test its practicality and utility. In the last activity, a journal paper (Paper III in the thesis) is presented to summarise all the processes. The communication is also carried out through pre-licentiate and the licentiate seminars. The extended-SAM shows in the result of the thesis that organisational culture is a clear factor that should be considered while assessing and studying BITA maturity. In addition, by considering organisational culture, assessing BITA is clearly shown as being more accurate and as reflecting a more detailed picture of the organisation’s BITA.

  • 38.
    El-Mekawy, Mohamed Sobih Aly
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    From Theory to Practice of Business-IT Alignment: Barriers, an Evaluation Framework and Relationships with Organisational Culture2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Business-IT alignment (BITA) continues to be a top management concern. It generally refers to a preferred condition in which the relationship between business and IT is optimised to maximise the business value of IT. Early approaches in both research and practice have focused on the role of IT in supporting business strategies. Today, a more extended approach of BITA has been embraced that recognises soft factors that are related to people and culture issues at both tactical and operational levels of organisations. ‘Why alignment is important’ is not the crucial question today. In fact ‘how it can be achieved and matured’ is the real concern of business executives. There exists a number of theoretical models for conceptualising BITA, however, they have different focuses and contain different BITA components. Therefore, there is a need for a means of supporting practitioners for selecting an appropriate model.

    Furthermore, there is a need for a more practice-oriented research that target higher maturity of BITA by understanding the organisational context, including barriers that hinders BITA and the mutual relationships between organisational culture and BITA. Thus, the overall problem addressed in the thesis is the following: In spite of extensive literature on business-IT alignment, there is still limited maturity of business-IT alignment in practice due to the limited knowledge on barriers that hinder BITA achievement from practitioners’ perspective, on the means for supporting the selection of an appropriate model for assessing BITA, and on mutual relationships between BITA and organisational culture.

    Based on this research problem, five research objectives were developed. The first two objectives corresponded to barriers to achieving BITA and supporting the selection of BITA model respectively. The remaining three objectives corresponded to the two unidirectional influences between BITA and organisational culture (OC) and to the mutual relationships between them respectively. Different research methodologies and strategies were applied to achieve the research objectives, including qualitative and quantitative studies as well as design science.

    The results presented in the thesis, each corresponding to an objective, are the following: 

    • A list of barriers that practitioners can use as a basis for better achievement of BITA, a better focus on strategic vs. tactical barriers, and their relationships to BITA components.
    • An evaluation framework that supports practitioners in selecting appropriate BITA models for assessing and modelling BITA.
    • An extended version of the strategic alignment model (SAM) of Luftman (2000), which considers organisational culture.
    • An analysis of the impact of BITA components on organisational culture profiles.
    • A BITA-organisational culture integrated view that supports decision-makers in facilitating decisions regarding both BITA and organisational culture.

    The results of the research provide both theoretical and empirical contributions to the business-IT alignment research and practice.

  • 39.
    Engström, Arvid
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Going Live: Collaborative Video Production After Television2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis explores social and creative practices that emerge with new mobile video technology. The work frames a design space that spans across both the social and technical domains. It associates emerging collaborative practices online with new means for producing and broadcasting media in real time, over mobile networks and using low-cost consumer technology just as these technologies are becoming widely available in the world. As a premise, we sketch a scenario where groups of non-professional users, enabled by new technology available in their mobile phones, produce live media collaboratively. We use detailed ethnographic inquiries into the practices of expert media producers to inform design and spur innovation of new technology. Over the course of the design research process, we have designed and developed two functional prototype systems and produced a number of theoretical contributions to the understanding of the collaborative mobile video space.

  • 40.
    Eriksson-Granskog, Agneta
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    General Metarules for Interactive Modular Construction of Natural Deduction Proofs2003Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis proposes a set of general metarules for interactive modular construction of natural deduction proofs.

    Interactive proof support systems are used for the construction of formal proofs in formal program development. They support the user interaction in the derivation of programs from specifications and in the development of proofs of properties of programs. Moreover, interactive proof support systems are often general theorem provers and provide general support for proof development. Natural deduction with its similarity to intuitive informal reasoning and its lucid proof explanations is ideal for interactive proof development. However, the formal proofs in formal program development tend to be long and detailed, and metarules for the development of proofs in natural deduction would give shorter proofs and facilitate the user interaction.

    The focus of the thesis is the characterization of general metarules for the interactive construction of proofs in natural deduction. The solution presented supports modularity and flexibility in interactive proof development and it provides interactive construction of proofs at metalevel and facilitates the presentation of the proofs at different levels of abstraction.

    The main contributions are:

    · General metarules for modular proof development.

    The general metarules for the interactive construction of derivations in natural deduction support the construction of proofs from proof parts. They compute parts of proofs on the demand of the user. By computing derived rules for each application, a user has important leeway in the number of rules to use.

    · Flexibility in the development of proofs.

    The flexibility in the interactive development of proofs is supported by general metarules for changes. The method for performing changes to proofs is based upon the replacement of parts of proofs.

    · A proof structure supporting the development of fragmentary proofs.

    · Explanations of proofs at different levels in accordance with the inference rules of natural deduction and the general metarules.

  • 41. Espinoza, Fredrik
    Individual service provisioning2003Doctoral thesis, comprehensive summary (Other academic)
  • 42.
    Essler, Ulf
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Analyzing Groupware Adoption: A Framework and Three Case Studies inLotus Notes Deployment1998Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The (business) value of information technology (IT) usage is debatable. The "computer paradox" is still in force. There is no demonstrable relationship between computer spending and organization profit. The purpose of this thesis is to analyze the critical first step in generating value through IT, i. e., the adoption process. One product (Lotus Notes) in one class of software (groupware) has been chosen. The study analyzes the adoption process, focusing on the project/departmental level, in three Swedish companies of varying size and in different lines of business. The study is based on three longitudinal (one year) case studies.

    The main results from the study with regard to the adoption are:

    • Adoption failed (completely and partially) in two cases and was (partially) successful in one case.
    • The foci in the three cases with regard to application(s) were firstly co-ordination and secondly communication. In no case was collaboration of (primary) interest.
    • The failed adoption attempts were characterized by; (1) a local point of introduction (combined with traditionally low central control within the companies); (2) little or no organizational Lotus Notes knowledge; (3) a complete dependence of external Lotus Notes consultants; (4) high ambitions about what the technology was going to accomplish.
    • The successful adoption were characterized by; (1) a central point of introduction (combined with a traditional, strong central control within the company); (2) good organizational Lotus Notes knowledge; (3) a clearly defined role for external Lotus Notes consultants; (4) moderate and clearly defined ambitions about what the technology was going to accomplish.

    The main results from the study with regard to the theoretical framework are:

    • The role of lead user is not a necessary factor for successful adoption. Local lead users (project leaders) were in a primary role in the failed adoption attempts.
    • Both Critical Mass Theory and the Sociotechnical Perspective are too simplistic with regard to technology adoption in an organizational setting.
      • In the Critical Mass Theory both technology aspects and management aspects need to be integrated, if applied to technology adoption.
      • In the Sociotechnical Perspective management aspects need to be integrated, if applied to technology adoption. Not taking into account organizational decision making and organizational hierarchies make the perspective less than useful, if applied in an organizational setting.
  • 43.
    Faraon, Montathar
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Co-creating democracy: Conceptualizing co-creative media to facilitate democratic engagement in society2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Internet-based information and communication technology (ICT) have increasingly been used to facilitate and support democratic engagement in society. A growing body of research has demonstrated that the Internet and, in particular, social media have given citizens the opportunity to participate, interact, network, collaborate, and mobilize themselves within communities. While these media have broadened the means of exercising citizenship in many forms of participatory democracy, the technological prerequisites exist to go beyond the standard uses of social media (e.g., social networking, entertainment) and towards proactive and co-creative democratic engagement. Such engagement includes, but is not limited to, participatory activities for democratic purposes. Further, some researchers have argued that representative democracy is in decline and has several limitations related to citizens' trust in politicians and engagement with representative institutions. There is a recognition among scholars to infuse representative democracy with participatory bottom-up processes by employing ICT in an attempt to bridge these limitations. In order to further facilitate and support participatory as well as co-creative processes, this thesis elaborates a concept of co-creative media.

    The process of this work was guided by the following question: How can co-creative media be theoretically anchored and conceptualized in order to facilitate and support citizen engagement within democratic processes? A concept-driven design research approach was adopted to address this research question, and this resulted in five interconnected articles. Firstly, based on the results from each article, four design guidelines were formulated to further guide the design of co-creative media for democratic engagement. These design guidelines may support future participatory design processes in which stakeholders collectively contribute to the development and evaluation of co-creative media. The guidelines constitute a resource that stakeholders may use to develop adaptations of co-creative media for the purposes of facilitating democratic engagement. Secondly, the results from each article were fed forward into the concept-driven research process as theoretical and empirical insights, which were used to inform and elaborate the main contribution of this thesis, namely the concept of co-creative media.

    The concept of co-creative media in its form outlined by this thesis seeks to broaden citizens’ democratic engagement by means of creating virtual spaces in which new ideas, initiatives, knowledge, solutions, and digital tools could emerge. The implications of co-creative media could be to create, develop, and strengthen partnerships between communities and local services, extend digital skills in society through community-engaged practitioners, and propagate as well as coordinate large-scale co-creative practices.

  • 44.
    Fasth, Tobias
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Decision Analysis in Situations with Conflicting Interests2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Decision problems in participatory decision making involve multiple stakeholders, who often have conflicting preferences concerning the actions under consideration. Decision problems such as these can be structured as multi-criteria problems, which enables the actions to be evaluated in terms of more than one single criterion. In these situations, the complexity of the problem increases when the objective is to select a portfolio of actions. Another aspect to take into consideration is that the choice of actions often has a long-term impact on the lives of the stakeholders. It is therefore not surprising that these problems often are sources of costly and time-consuming conflicts.

    This thesis presents artifacts in the form of methods and applications aiding the decision maker in participatory decision making problems in highlighting stakeholder conflict. The artifacts are DANCE, XPLOR, POLA, and SENS. DANCE is a framework of methods that are used to elicit preferences, and to measure and analyze conflicts between and within stakeholder groups regarding the performance of an action. The framework uses three novel artifacts: i) CAR-CE a method for preference elicitation, ii) two indices, one for measuring the conflict within one stakeholder group, one for measuring the conflict between two stakeholder groups, and iii) an approach to portfolio optimisation and robustness analysis. XPLOR is a web-application that is used to explore and visualise stakeholder conflicts. POLA is a web-application for evaluating commercial development policy in cooperation with key stakeholders. The last artifact, SENSE, is a method for sensitivity analysis of portfolios.

    The artifact development followed the design science methodology, where the aim of the artifact is to solve a practical problem and where, in this case, the artifacts were evaluated against a set of requirements. The preference elicitation method, CAR-CE, was implemented in a web-questionnaire and was used in a real-world survey in cooperation with Upplands Väsby municipality. The elicited preferences were used in illustrative scenarios to demonstrate both the DANCE framework and XPLOR. POLA was demonstrated in three examples based on results from workshops that were conducted together with the municipalities of Norrköping, Katrineholm and Filipstad. Altogether, these artifacts support decision makers in modeling and analyzing decision problems, with the purpose of avoiding future costly and time-consuming conflicts in land use planning.

  • 45.
    Fernaeus, Ylva
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Let's Make a Digital Patchwork: Designing for Childrens Creative Play with Programming Materials2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis explores new approaches to making and playing with programming materials, especially the forms provided with screen-based digital media. Designing with these media expressions can be very attractive to children, but they are usually not made available to them in the same degree as are physical materials.

    Inspired by children's play with physical materials, this work includes design explorations of how different resources alter, scaffold and support children in activities of making dynamic, screen-based systems. How tangibles turn the activity of programming into a more physical, social and collaborative activity is emphasised. A specific outcome concerns the importance of considering 'offline' and socially oriented action when designing tangible technologies. The work includes the design of a tangible programming system, Patcher, with which groups of children can program systems displayed on a large screen surface.

    The character of children's programming is conceptualised through the notion of a digital patchwork, emphasising (1) children's programming as media-sensitive design, (2) making programming more concrete by combining and reusing readily available programming constructs, and (3) the use of tangibles for social interaction.

  • 46.
    Gamukama, Elly Amani
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Analytical modelling of Internet provision and usage in context of development through a utility based framework2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Information and communication technology and development (ICTD) is a research area that has broadly captured the attention of the public and the academics in the last two decades. It deals with the interaction and the relations between the humans and the society in general on one side and the technology on the other side. The focus in this thesis is on the computing and communication technology, herein referred to as the “Internet – the IP based technology”, which is seen as one of the enablers for economic and social growth.

    The benefit of the Internet connectivity and usage in inducing and enhancing positive social changes in basic dimensions of human life is generally accepted as one of the most important drivers for development. The success and the inevitability of the Internet in the developed world underline its proliferation and diffusion essential in less developed countries. However, sometimes these processes are being impaired by unintended and intended consequences created by the social dynamics that drives the current information technological innovations and evolutions, stakeholders’ desire of fulfilling one’s utility egos, all coupled with market environments.

    This thesis takes an insight in both unintended and intended implications and their effects on enabling development in the environments where the Internet Protocol (IP) based infrastructures are limited like in Least Developing regions/countries.  The results of this insight study have led in;

    a)      Establishing the basic Internet services that would trigger the exploitation of one’s potential for development.

    This has been achieved through the use of analytical scientific methods to classify Internet traffic characteristics and derive the relevance levels of their corresponding Internet services groups in fostering development.

    b)      Developing a framework that lays down structure guidelines to facilitate Decision Makers especially in least developed countries to make scientifically informed subjective judgements for Internet services in the context of development.

    c)      Designing and developing of the Internet Services in the Context of Developing (ISCD) model that enables the alignment of the apparent divergent/misalignment objectives of Internet stakeholders in the present Internet structure to have their respective maximised intended benefits.

    Empirical testing of the model led in setting strategic options for aligning stakeholders goals in view of the ISCD along two main domains (i) network management policies – that focuses on provisions of services, and (ii) Internet consumption/usage – that focus on services relevance, commensurability to specific requirements as pertains LDCs, and services delivery mechanism convergence to all-IP.

  • 47.
    Giannoulis, Constantinos
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Model-driven Alignment: Linking Business Strategy with Information Systems2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Information technology (IT) is more pervasive than ever before, constituting a significant factor for performance and survival in the business arena. It is essential that IT within organizations understands what the Business needs in order to provide the necessary support and bring value, which is also true when IT is also the main value creator. Therefore, alignment between the Business and IT within organizations is an issue of great concern and it is still open for solvency both for business and IT executives and practitioners.

    This work is scoped to the alignment linkage between business strategy and information systems (IS), where business strategy typically constitutes the primary exponent of the Business and IS typically encapsulates the elements of IT sustaining an organization. Current approaches are either focused on detailed aspects of IS and treat business strategy abstractly or use distinct business strategy formulations (e.g. Value Chain) but deal with IS only partially. This is problematic because the abstract use of business strategy hinders traceability of strategic intentions and initiatives towards features/aspects of IS, which are aimed to actualize and support such intentions. Because approaches using distinct business strategy formulations are not relevant to all organizations and are limited only to the IS aspects addressed.

    Introducing a model-driven approach for the alignment linkage is aimed at addressing the outlined shortcomings. Following a design science research paradigm, the main artifact developed is the Unified Business Strategy Meta-Model (UBSMM), which is based on conceptualizing established business strategy formulations (e.g. Value Chain) and integrating them. UBSMM supports mappings to IS models used in organizations, such as IS requirements, enterprise models and enterprise architecture, and provides unambiguous utilization of business strategy for the alignment linkage.

    Contributions of this thesis are grounded both on the process of building UBSMM and mapping to IS models, as well as the artifact itself. Conceptualizing and integrating business strategy formulations provides a less ambiguous and unified view of strategic concepts. This limits variations in interpretation and reinforces mappings to IS models, which are defined based on inter-schema properties across models. Therefore, UBSMM can link business strategy to IS models enhancing their communication in a traceable manner, ergo, support alignment.

  • 48.
    Guerrero Razuri, Javier Francisco
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Decisional-Emotional Support System for a Synthetic Agent: Influence of Emotions in Decision-Making Toward the Participation of Automata in Society2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Emotion influences our actions, and this means that emotion has subjective decision value. Emotions, properly interpreted and understood, of those affected by decisions provide feedback to actions and, as such, serve as a basis for decisions. Accordingly, "affective computing" represents a wide range of technological opportunities toward the implementation of emotions to improve human-computer interaction, which also includes insights across a range of contexts of computational sciences into how we can design computer systems to communicate and recognize the emotional states provided by humans. Today, emotional systems such as software-only agents and embodied robots seem to improve every day at managing large volumes of information, and they remain emotionally incapable to read our feelings and react according to them. From a computational viewpoint, technology has made significant steps in determining how an emotional behavior model could be built; such a model is intended to be used for the purpose of intelligent assistance and support to humans. Human emotions are engines that allow people to generate useful responses to the current situation, taking into account the emotional states of others. Recovering the emotional cues emanating from the natural behavior of humans such as facial expressions and bodily kinetics could help to develop systems that allow recognition, interpretation, processing, simulation, and basing decisions on human emotions. Currently, there is a need to create emotional systems able to develop an emotional bond with users, reacting emotionally to encountered situations with the ability to help, assisting users to make their daily life easier. Handling emotions and their influence on decisions can improve the human-machine communication with a wider vision. The present thesis strives to provide an emotional architecture applicable for an agent, based on a group of decision-making models influenced by external emotional information provided by humans, acquired through a group of classification techniques from machine learning algorithms. The system can form positive bonds with the people it encounters when proceeding according to their emotional behavior. The agent embodied in the emotional architecture will interact with a user, facilitating their adoption in application areas such as caregiving to provide emotional support to the elderly. The agent's architecture uses an adversarial structure based on an Adversarial Risk Analysis framework with a decision analytic flavor that includes models forecasting a human's behavior and their impact on the surrounding environment. The agent perceives its environment and the actions performed by an individual, which constitute the resources needed to execute the agent's decision during the interaction. The agent's decision that is carried out from the adversarial structure is also affected by the information of emotional states provided by a classifiers-ensemble system, giving rise to a "decision with emotional connotation" included in the group of affective decisions. The performance of different well-known classifiers was compared in order to select the best result and build the ensemble system, based on feature selection methods that were introduced to predict the emotion. These methods are based on facial expression, bodily gestures, and speech, with satisfactory accuracy long before the final system.

  • 49.
    Gurung, Ram Bahadur
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Learning Decision Trees and Random Forests from Histogram Data: An application to component failure prediction for heavy duty trucks2017Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    A large volume of data has become commonplace in many domains these days. Machine learning algorithms can be trained to look for any useful hidden patterns in such data. Sometimes, these big data might need to be summarized to make them into a manageable size, for example by using histograms, for various reasons. Traditionally, machine learning algorithms can be trained on data expressed as real numbers and/or categories but not on a complex structure such as histogram. Since machine learning algorithms that can learn from data with histograms have not been explored to a major extent, this thesis intends to further explore this domain.

    This thesis has been limited to classification algorithms, tree-based classifiers such as decision trees, and random forest in particular. Decision trees are one of the simplest and most intuitive algorithms to train. A single decision tree might not be the best algorithm in term of its predictive performance, but it can be largely enhanced by considering an ensemble of many diverse trees as a random forest. This is the reason why both algorithms were considered. So, the objective of this thesis is to investigate how one can adapt these algorithms to make them learn better on histogram data. Our proposed approach considers the use of multiple bins of a histogram simultaneously to split a node during the tree induction process. Treating bins simultaneously is expected to capture dependencies among them, which could be useful. Experimental evaluation of the proposed approaches was carried out by comparing them with the standard approach of growing a tree where a single bin is used to split a node. Accuracy and the area under the receiver operating characteristic (ROC) curve (AUC) metrics along with the average time taken to train a model were used for comparison. For experimental purposes, real-world data from a large fleet of heavy duty trucks were used to build a component-failure prediction model. These data contain information about the operation of trucks over the years, where most operational features are summarized as histograms. Experiments were performed further on the synthetically generated dataset. From the results of the experiments, it was observed that the proposed approach outperforms the standard approach in performance and compactness of the model but lags behind in terms of training time. This thesis was motivated by a real-life problem encountered in the operation of heavy duty trucks in the automotive industry while building a data driven failure-prediction model. So, all the details about collecting and cleansing the data and the challenges encountered while making the data ready for training the algorithm have been presented in detail.

  • 50.
    Gurung, Ram Bahadur
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Random Forest for Histogram Data: An application in data-driven prognostic models for heavy-duty trucks2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Data mining and machine learning algorithms are trained on large datasets to find useful hidden patterns. These patterns can help to gain new insights and make accurate predictions. Usually, the training data is structured in a tabular format, where the rows represent the training instances and the columns represent the features of these instances. The feature values are usually real numbers and/or categories. As very large volumes of digital data are becoming available in many domains, the data is often summarized into manageable sizes for efficient handling. To aggregate data into histograms is one means to reduce the size of the data. However, traditional machine learning algorithms have a limited ability to learn from such data, and this thesis explores extensions of the algorithms to allow for more effective learning from histogram data.

    The thesis focuses on the decision tree and random forest algorithms, which are easy to understand and implement. Although, a single decision tree may not result in the highest predictive performance, one of its benefits is that it often allows for easy interpretation. By combining many such diverse trees into a random forest, the performance can be greatly enhanced, however at the cost of reduced interpretability. By first finding out how to effectively train a single decision tree from histogram data, these findings could be carried over to building robust random forests from such data. The overarching research question for the thesis is: How can the random forest algorithm be improved to learn more effectively from histogram data, and how can the resulting models be interpreted? An experimental approach was taken, under the positivist paradigm, in order to answer the question. The thesis investigates how the standard decision tree and random forest algorithms can be adapted to make them learn more accurate models from histogram data. Experimental evaluations of the proposed changes were carried out on both real world data and synthetically generated experimental data. The real world data was taken from the automotive domain, concerning the operation and maintenance of heavy-duty trucks. Component failure prediction models were built from the operational data of a large fleet of trucks, where the information about their operation over many years have been summarized as histograms. The experimental results showed that the proposed approaches were more effective than the original algorithms, which treat bins of histograms as separate features. The thesis also contributes towards the interpretability of random forests by evaluating an interactive visual tool for assisting users to understand the reasons behind the output of the models.

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