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Weegar, Rebecka
Publications (10 of 26) Show all publications
Weegar, R. & Idestam-Almquist, P. (2024). Reducing Workload in Short Answer Grading Using Machine Learning. International Journal of Artificial Intelligence in Education, 34, 247-273
Open this publication in new window or tab >>Reducing Workload in Short Answer Grading Using Machine Learning
2024 (English)In: International Journal of Artificial Intelligence in Education, ISSN 1560-4292, E-ISSN 1560-4306, Vol. 34, p. 247-273Article in journal (Refereed) Published
Abstract [en]

Machine learning methods can be used to reduce the manual workload in exam grading, making it possible for teachers to spend more time on other tasks. However, when it comes to grading exams, fully eliminating manual work is not yet possible even with very accurate automated grading, as any grading mistakes could have significant consequences for the students. Here, the evaluation of an automated grading approach is therefore extended from measuring workload in relation to the accuracy of automated grading, to also measuring the overall workload required to correctly grade a full exam, with and without the support of machine learning. The evaluation was performed during an introductory computer science course with over 400 students. The exam consisted of 64 questions with relatively short answers and a two-step approach for automated grading was applied. First, a subset of answers to the exam questions was manually graded and next used as training data for machine learning models classifying the remaining answers. A number of different strategies for how to select which answers to include in the training data were evaluated. The time spent on different grading actions was measured along with the reduction of effort using clustering of answers and automated scoring. Compared to fully manual grading, the overall reduction of workload was substantial-between 64% and 74%-even with a complete manual review of all classifier output to ensure a fair grading.

Keywords
Short answer grading, Automatic grading, Machine learning, Cluster based sampling
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:su:diva-215837 (URN)10.1007/s40593-022-00322-1 (DOI)000939029000001 ()2-s2.0-85149044532 (Scopus ID)
Available from: 2023-03-29 Created: 2023-03-29 Last updated: 2024-09-16Bibliographically approved
Verberk, J. D. M., van der Werff, S. D., Weegar, R., Henriksson, A., Richir, M. C., Buchli, C., . . . Naucler, P. (2023). The augmented value of using clinical notes in semi-automated surveillance of deep surgical site infections after colorectal surgery. Antimicrobial Resistance and Infection Control, 12(1), Article ID 117.
Open this publication in new window or tab >>The augmented value of using clinical notes in semi-automated surveillance of deep surgical site infections after colorectal surgery
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2023 (English)In: Antimicrobial Resistance and Infection Control, E-ISSN 2047-2994, Vol. 12, no 1, article id 117Article in journal (Refereed) Published
Abstract [en]

BackgroundIn patients who underwent colorectal surgery, an existing semi-automated surveillance algorithm based on structured data achieves high sensitivity in detecting deep surgical site infections (SSI), however, generates a significant number of false positives. The inclusion of unstructured, clinical narratives to the algorithm may decrease the number of patients requiring manual chart review. The aim of this study was to investigate the performance of this semi-automated surveillance algorithm augmented with a natural language processing (NLP) component to improve positive predictive value (PPV) and thus workload reduction (WR).MethodsRetrospective, observational cohort study in patients who underwent colorectal surgery from January 1, 2015, through September 30, 2020. NLP was used to detect keyword counts in clinical notes. Several NLP-algorithms were developed with different count input types and classifiers, and added as component to the original semi-automated algorithm. Traditional manual surveillance was compared with the NLP-augmented surveillance algorithms and sensitivity, specificity, PPV and WR were calculated.ResultsFrom the NLP-augmented models, the decision tree models with discretized counts or binary counts had the best performance (sensitivity 95.1% (95%CI 83.5-99.4%), WR 60.9%) and improved PPV and WR by only 2.6% and 3.6%, respectively, compared to the original algorithm.ConclusionsThe addition of an NLP component to the existing algorithm had modest effect on WR (decrease of 1.4-12.5%), at the cost of sensitivity. For future implementation it will be a trade-off between optimal case-finding techniques versus practical considerations such as acceptability and availability of resources.

Keywords
Automated surveillance, Algorithm, Colorectal surgery, Healthcare-associated infections, Natural language processing, Surgical site infections
National Category
Health Sciences Biological Sciences Basic Medicine Infectious Medicine
Research subject
Computer and Systems Sciences
Identifiers
urn:nbn:se:su:diva-223746 (URN)10.1186/s13756-023-01316-x (DOI)001088059900001 ()37884948 (PubMedID)2-s2.0-85174855329 (Scopus ID)
Available from: 2023-11-17 Created: 2023-11-17 Last updated: 2023-11-23Bibliographically approved
Wu, Y., Nouri, J., Li, X., Weegar, R., Afzaal, M. & Aayesha, A. (. (2021). A Word Embeddings Based Clustering Approach for Collaborative Learning Group Formation. In: Ido Roll; Danielle McNamara; Sergey Sosnovsky; Rose Luckin; Vania Dimitrova (Ed.), Artificial Intelligence in Education: 22nd International Conference, AIED 2021, Utrecht, The Netherlands, June 14–18, 2021, Proceedings, Part II. Paper presented at International Conference, AIED 2021, Utrecht, The Netherlands, June 14–18, 2021 (pp. 395-400). Springer Nature
Open this publication in new window or tab >>A Word Embeddings Based Clustering Approach for Collaborative Learning Group Formation
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2021 (English)In: Artificial Intelligence in Education: 22nd International Conference, AIED 2021, Utrecht, The Netherlands, June 14–18, 2021, Proceedings, Part II / [ed] Ido Roll; Danielle McNamara; Sergey Sosnovsky; Rose Luckin; Vania Dimitrova, Springer Nature , 2021, p. 395-400Conference paper, Published paper (Refereed)
Abstract [en]

Today, collaborative learning has become quite central as a method for learning, and over the past decades, a large number of studies have demonstrated the benefits from various theoretical and methodological perspectives. This study proposes a novel approach that utilises Natural Language Processing(NLP) methods, particularly pre-trained word embeddings, to automatically create homogeneous or heterogeneous groups of students in terms of knowledge and knowledge gaps expressed in assessments. The two different ways of creating groups serve two different pedagogical purposes: (1) homogeneous group formation based on students’ knowledge can support and make teachers’ pedagogical activities such as feedback provision more time efficient, and (2) the heterogeneous groups can support and enhance collaborative learning. We evaluate the performance of the proposed approach through experiments with a dataset from a university course in programming didactics.

Place, publisher, year, edition, pages
Springer Nature, 2021
Series
Lecture Notes in Computer Science (LNCS), ISSN 0302-9743, E-ISSN 1611-3349 ; 12749
Keywords
Collaborative learning, Artificial intelligence, Natural language processing, Word embeddings, AI, NLP
National Category
Computer Sciences
Research subject
Computer and Systems Sciences
Identifiers
urn:nbn:se:su:diva-200598 (URN)10.1007/978-3-030-78270-2_70 (DOI)978-3-030-78270-2 (ISBN)978-3-030-78269-6 (ISBN)
Conference
International Conference, AIED 2021, Utrecht, The Netherlands, June 14–18, 2021
Available from: 2022-01-08 Created: 2022-01-08 Last updated: 2022-01-11Bibliographically approved
Aayesha, A., Nouri, J., Afzaal, M., Wu, Y., Li, X. & Weegar, R. (2021). An Ensemble Approach for Question-Level Knowledge Tracing. In: Ido Roll; Danielle McNamara; Sergey Sosnovsky; Rose Luckin; Vania Dimitrova (Ed.), Artificial Intelligence in Education: 22nd International Conference, AIED 2021, Utrecht, The Netherlands, June 14–18, 2021, Proceedings, Part II. Paper presented at International Conference on Artificial Intelligence in Education, Utrecht, The Netherlands, June 14–18, 2021 (pp. 433-437). Cham: Springer
Open this publication in new window or tab >>An Ensemble Approach for Question-Level Knowledge Tracing
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2021 (English)In: Artificial Intelligence in Education: 22nd International Conference, AIED 2021, Utrecht, The Netherlands, June 14–18, 2021, Proceedings, Part II / [ed] Ido Roll; Danielle McNamara; Sergey Sosnovsky; Rose Luckin; Vania Dimitrova, Cham: Springer , 2021, p. 433-437Conference paper, Published paper (Refereed)
Abstract [en]

Knowledge tracing—where a machine models the students’ knowledge as they interact with coursework—is a well-established area in the field of Artificial Intelligence in Education. In this paper, an ensemble approach is proposed that addresses existing limitations in question-centric knowledge tracing and achieves the goal of predicting future question correctness. The proposed approach consists of two models; one is Light Gradient Boosting Machine (LightGBM) built by incorporating all relevant key features engineered from the data. The second model is a Multiheaded-Self-Attention Knowledge Tracing model (MSAKT) that extracts historical student knowledge of future question by calculating their contextual similarity with previously attempted questions. The proposed model’s effectiveness is evaluated by conducting experiments on a big Kaggle dataset achieving an Area Under ROC Curve (AUC) score of 0.84 with 84% accuracy using 10fold cross-validation.

Place, publisher, year, edition, pages
Cham: Springer, 2021
Series
Lecture Notes in Computer Science (LNCS), ISSN 0302-9743, E-ISSN 1611-3349 ; 12749
Keywords
Adaptive learning, Knowledge tracing, Question-level prediction, Artificial Intelligence, Intelligent education
National Category
Computer Sciences
Research subject
Computer and Systems Sciences
Identifiers
urn:nbn:se:su:diva-200599 (URN)10.1007/978-3-030-78270-2_77 (DOI)978-3-030-78270-2 (ISBN)978-3-030-78269-6 (ISBN)
Conference
International Conference on Artificial Intelligence in Education, Utrecht, The Netherlands, June 14–18, 2021
Available from: 2022-01-08 Created: 2022-01-08 Last updated: 2024-08-15Bibliographically approved
Afzaal, M., Nouri, J., Aayesha, A., Papapetrou, P., Fors, U., Wu, Y., . . . Weegar, R. (2021). Automatic and Intelligent Recommendations to Support Students’ Self-Regulation. In: International Conference on Advanced Learning Technologies (ICALT),: . Paper presented at 2021 International Conference on Advanced Learning Technologies (ICALT),12-15 July 2021 Tartu, Estonia (pp. 336-338).
Open this publication in new window or tab >>Automatic and Intelligent Recommendations to Support Students’ Self-Regulation
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2021 (English)In: International Conference on Advanced Learning Technologies (ICALT),, 2021, p. 336-338Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, we propose a counterfactual explanations-based approach to provide an automatic and intelligent recommendation that supports student's self-regulation of learning in a data-driven manner, aiming to improve their performance in courses. Existing work under the fields of learning analytics and AI in education predict students' performance and use the prediction outcome as feedback without explaining the reasons behind the prediction. Our proposed approach developed an algorithm that explains the root causes behind student's performance decline and generates data-driven recommendations for action. The effectiveness of the proposed predictive model that constitutes the intelligent recommendations is evaluated, with results demonstrating high accuracy.

Series
International Conference on Advanced Learning Technologies (ICALT), ISSN 2161-3761, E-ISSN 2161-377X
Keywords
Learning analytics, Counterfactual Explanations, Intelligent Recommendations, Self-Regulation, Artificial Intelligence
National Category
Computer Sciences
Research subject
Computer and Systems Sciences
Identifiers
urn:nbn:se:su:diva-200362 (URN)10.1109/ICALT52272.2021.00107 (DOI)978-1-6654-4106-3 (ISBN)
Conference
2021 International Conference on Advanced Learning Technologies (ICALT),12-15 July 2021 Tartu, Estonia
Available from: 2022-01-04 Created: 2022-01-04 Last updated: 2022-01-10Bibliographically approved
Wu, Y., Nouri, J., Li, X., Weegar, R., Afzaal, M. & Aayesha, A. (. (2021). Catching Group Criteria Semantic Information When Forming Collaborative Learning Groups. In: Tinne De Laet; Roland Klemke; Carlos Alario-Hoyos; Isabel Hilliger; Alejandro Ortega-Arranz (Ed.), Technology-Enhanced Learning for a Free, Safe, and Sustainable World: 16th European Conference on Technology Enhanced Learning, EC-TEL 2021, Bolzano, Italy, September 20-24, 2021, Proceedings. Paper presented at European Conference on Technology Enhanced Learning, EC-TEL 2021, Bolzano, Italy, September 20-24, 2021 (pp. 16-27). Springer
Open this publication in new window or tab >>Catching Group Criteria Semantic Information When Forming Collaborative Learning Groups
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2021 (English)In: Technology-Enhanced Learning for a Free, Safe, and Sustainable World: 16th European Conference on Technology Enhanced Learning, EC-TEL 2021, Bolzano, Italy, September 20-24, 2021, Proceedings / [ed] Tinne De Laet; Roland Klemke; Carlos Alario-Hoyos; Isabel Hilliger; Alejandro Ortega-Arranz, Springer , 2021, p. 16-27Conference paper, Published paper (Refereed)
Abstract [en]

Collaborative learning has grown more popular as a form of instruction in recent decades, with a significant number of studies demonstrating its benefits from many perspectives of theory and methodology. However, it has also been demonstrated that effective collaborative learning does not occur spontaneously without orchestrating collaborative learning groups according to the provision of favourable group criteria. Researchers have investigated different foundations and strategies to form such groups. However, the group criteria semantic information, which is essential for classifying groups, has not been explored. To capture the group criteria semantic information, we propose a novel Natural Language Processing (NLP) approach, namely using pre-trained word embedding. Through our approach, we could automatically form homogeneous and heterogeneous collaborative learning groups based on student’s knowledge levels expressed in assessments. Experiments utilising a dataset from a university programming course are used to assess the performance of the proposed approach.

Place, publisher, year, edition, pages
Springer, 2021
Series
Lecture Notes in Computer Science (LNCS), ISSN 0302-9743, E-ISSN 1611-3349 ; 12884
Keywords
Collaborative learning group formation, Word embeddings, Natural Language Processing, Semantic information, Artificial Intelligence
National Category
Computer Sciences
Research subject
Computer and Systems Sciences
Identifiers
urn:nbn:se:su:diva-200604 (URN)10.1007/978-3-030-86436-1_2 (DOI)978-3-030-86436-1 (ISBN)978-3-030-86435-4 (ISBN)
Conference
European Conference on Technology Enhanced Learning, EC-TEL 2021, Bolzano, Italy, September 20-24, 2021
Available from: 2022-01-08 Created: 2022-01-08 Last updated: 2024-10-30Bibliographically approved
Afzaal, M., Nouri, J., Zia, A., Papapetrou, P., Fors, U., Wu, Y., . . . Weegar, R. (2021). Explainable AI for Data-Driven Feedback and Intelligent Action Recommendations to Support Students Self-Regulation. Frontiers in Artificial Intelligence, 4, Article ID 723447.
Open this publication in new window or tab >>Explainable AI for Data-Driven Feedback and Intelligent Action Recommendations to Support Students Self-Regulation
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2021 (English)In: Frontiers in Artificial Intelligence, E-ISSN 2624-8212, Vol. 4, article id 723447Article in journal (Refereed) Published
Abstract [en]

Formative feedback has long been recognised as an effective tool for student learning, and researchers have investigated the subject for decades. However, the actual implementation of formative feedback practices is associated with significant challenges because it is highly time-consuming for teachers to analyse students’ behaviours and to formulate and deliver effective feedback and action recommendations to support students’ regulation of learning. This paper proposes a novel approach that employs learning analytics techniques combined with explainable machine learning to provide automatic and intelligent feedback and action recommendations that support student’s self-regulation in a data-driven manner, aiming to improve their performance in courses. Prior studies within the field of learning analytics have predicted students’ performance and have used the prediction status as feedback without explaining the reasons behind the prediction. Our proposed method, which has been developed based on LMS data from a university course, extends this approach by explaining the root causes of the predictions and by automatically providing data-driven intelligent recommendations for action. Based on the proposed explainable machine learning-based approach, a dashboard that provides data-driven feedback and intelligent course action recommendations to students is developed, tested and evaluated. Based on such an evaluation, we identify and discuss the utility and limitations of the developed dashboard. According to the findings of the conducted evaluation, the dashboard improved students’ learning outcomes, assisted them in self-regulation and had a positive effect on their motivation.

Keywords
self-regulated learning, recommender system, automatic data-driven feedback, explainable machine learning-based approach, dashboard, learning analytics, AI
National Category
Computer Sciences
Research subject
Computer and Systems Sciences
Identifiers
urn:nbn:se:su:diva-200479 (URN)10.3389/frai.2021.723447 (DOI)000751704800142 ()
Available from: 2022-01-05 Created: 2022-01-05 Last updated: 2024-08-14Bibliographically approved
Afzaal, M., Nouri, J., Aayesha, A., Papapetrou, P., Fors, U., Wu, Y., . . . Weegar, R. (2021). Generation of Automatic Data-Driven Feedback to Students Using Explainable Machine Learning. In: Ido Roll; Danielle McNamara; Sergey Sosnovsky; Rose Luckin; Vania Dimitrova (Ed.), Artificial Intelligence in Education: 22nd International Conference, AIED 2021, Utrecht, The Netherlands, June 14–18, 2021, Proceedings, Part II. Paper presented at 22nd International Conference, AIED 2021, Utrecht, The Netherlands, June 14–18, 2021 (pp. 37-42). Springer
Open this publication in new window or tab >>Generation of Automatic Data-Driven Feedback to Students Using Explainable Machine Learning
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2021 (English)In: Artificial Intelligence in Education: 22nd International Conference, AIED 2021, Utrecht, The Netherlands, June 14–18, 2021, Proceedings, Part II / [ed] Ido Roll; Danielle McNamara; Sergey Sosnovsky; Rose Luckin; Vania Dimitrova, Springer , 2021, p. 37-42Conference paper, Published paper (Refereed)
Abstract [en]

This paper proposes a novel approach that employs learning analytics techniques combined with explainable machine learning to provide automatic and intelligent actionable feedback that supports students self-regulation of learning in a data-driven manner. Prior studies within the field of learning analytics predict students’ performance and use the prediction status as feedback without explaining the reasons behind the prediction. Our proposed method, which has been developed based on LMS data from a university course, extends this approach by explaining the root causes of the predictions and automatically provides data-driven recommendations for action. The underlying predictive model effectiveness of the proposed approach is evaluated, with the results demonstrating 90 per cent accuracy.

Place, publisher, year, edition, pages
Springer, 2021
Series
Lecture Notes in Computer Science (LNCS), ISSN 0302-9743, E-ISSN 1611-3349 ; 12749
Keywords
Learning analytics, Explainable machine learning, Feedback provision, Recommendations generation, Dashboard
National Category
Computer Sciences
Research subject
Computer and Systems Sciences
Identifiers
urn:nbn:se:su:diva-200483 (URN)10.1007/978-3-030-78270-2_6 (DOI)978-3-030-78270-2 (ISBN)
Conference
22nd International Conference, AIED 2021, Utrecht, The Netherlands, June 14–18, 2021
Available from: 2022-01-05 Created: 2022-01-05 Last updated: 2024-08-14Bibliographically approved
Weegar, R. (2020). Mining Clinical Text in Cancer Care. (Doctoral dissertation). Stockholm: Department of Computer and Systems Sciences, Stockholm University
Open this publication in new window or tab >>Mining Clinical Text in Cancer Care
2020 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Health care and clinical practice generate large amounts of text detailing symptoms, test results, diagnoses, treatments, and outcomes for patients. This clinical text, documented in health records, is a potential source of knowledge and an underused resource for improved health care. The focus of this work has been text mining of clinical text in the domain of cancer care, with the aim to develop and evaluate methods for extracting relevant information from such texts. Two different types of clinical documentation have been included: clinical notes from electronic health records in Swedish and Norwegian pathology reports.

Free text, and clinical text in particular, is considered as a kind of unstructured information, which is difficult to process automatically. Therefore, information extraction can be applied to create a more structured representation of a text, making its content more accessible for machine learning and statistics. To this end, this thesis describes the development of an efficient and accurate tool for information extraction for pathology reports.

Another application for clinical text mining is risk prediction and diagnosis prediction. The goal for such prediction is to create a machine learning model capable of identifying patients at risk of a specific disease or some other adverse outcome. The motivation for cancer diagnosis prediction is that an early diagnosis can be beneficial for the outcome of treatment. Here, a disease prediction model was developed and evaluated for prediction of cervical cancer. To create this model, health records of patients diagnosed with cervical cancer were processed in two steps. First, clinical events were extracted from free text clinical notes through the use of named entity recognition. The extracted events were next combined with other event types, such as diagnosis codes and drug codes from the same health records. Finally, machine learning models were trained for predicting cervical cancer, and evaluation showed that events extracted from the free text records were the most informative event type for the diagnosis prediction.

Place, publisher, year, edition, pages
Stockholm: Department of Computer and Systems Sciences, Stockholm University, 2020. p. 64
Series
Report Series / Department of Computer & Systems Sciences, ISSN 1101-8526 ; 20-001
Keywords
text mining, natural language processing, electronic health records, clinical text mining, information extraction
National Category
Computer and Information Sciences
Research subject
Computer and Systems Sciences
Identifiers
urn:nbn:se:su:diva-176282 (URN)978-91-7797-911-1 (ISBN)978-91-7797-912-8 (ISBN)
Public defence
2020-01-27, L30, NOD-huset, Borgarfjordsgatan 12, Kista, 13:00 (English)
Opponent
Supervisors
Note

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Accepted. Paper 5: Submitted.

Available from: 2019-12-19 Created: 2019-11-28 Last updated: 2022-02-26Bibliographically approved
Weegar, R. & Sundstrom, K. (2020). Using machine learning for predicting cervical cancer from Swedish electronic health records by mining hierarchical representations. PLOS ONE, 15(8), Article ID e0237911.
Open this publication in new window or tab >>Using machine learning for predicting cervical cancer from Swedish electronic health records by mining hierarchical representations
2020 (English)In: PLOS ONE, E-ISSN 1932-6203, Vol. 15, no 8, article id e0237911Article in journal (Refereed) Published
Abstract [en]

Electronic health records (EHRs) contain rich documentation regarding disease symptoms and progression, but EHR data is challenging to use for diagnosis prediction due to its high dimensionality, relative scarcity, and substantial level of noise. We investigated how to best represent EHR data for predicting cervical cancer, a serious disease where early detection is beneficial for the outcome of treatment. A case group of 1321 patients with cervical cancer were matched to ten times as many controls, and for both groups several types of events were extracted from their EHRs. These events included clinical codes, lab results, and contents of free text notes retrieved using a LSTM neural network. Clinical events are described with great variation in EHR texts, leading to a very large feature space. Therefore, an event hierarchy inferred from the textual events was created to represent the clinical texts. Overall, the events extracted from free text notes contributed the most to the final prediction, and the hierarchy of textual events further improved performance. Four classifiers were evaluated for predicting a future cancer diagnosis where Random Forest achieved the best results with an AUC of 0.70 from a year before diagnosis up to 0.97 one day before diagnosis. We conclude that our approach is sound and had excellent discrimination at diagnosis, but only modest discrimination capacity before this point. Since our study objective was earlier disease prediction than such, we propose further work should consider extending patient histories through e.g. the integration of primary health records preceding referral to hospital.

National Category
Computer and Information Sciences
Research subject
Computer and Systems Sciences
Identifiers
urn:nbn:se:su:diva-186666 (URN)10.1371/journal.pone.0237911 (DOI)000564080300039 ()32822401 (PubMedID)
Available from: 2020-11-20 Created: 2020-11-20 Last updated: 2022-02-25Bibliographically approved
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