Many would agree that learning occurs when new information is stored in memory. Therefore, most learning efforts typically focus on encoding processes, such as additional study or other forms of repetition. However, as I will outline in this thesis, there are other means by which to improve memory, such as retrieval practice in the form of tests. Testing memory has a reinforcing effect on memory, and it improves retention more than an equal amount of repeated study – referred to as the testing effect – and it has been assumed that retrieval processes drive this effect. Recently, however, this assumption has been called into question because of findings that suggest that articulation, that is, the act of providing an explicit response on a memory test, may play a role in determining the magnitude of the testing effect. Therefore, in three studies, I have examined the effects of retrieval and articulation on later retention, in an attempt to ascertain whether the testing effect is entirely driven by retrieval, or if there are additive effects of articulation. I have also explored possible boundary conditions that may determine when, and if, the effects of retrieval and articulation become selective with respect to memory performance. In all three studies, participants studied paired associates and were tested in a cued recall paradigm after a short (~5 min) and a long (1 week) retention interval, and retrieval was either covert (i.e., responses were retrieved but not articulated) or overt (i.e., responses were retrieved and articulated). 

In Study I, I demonstrated that uninstructed covert retrieval practice (by means of delayed judgments of learning) produced a testing effect (i.e., improved memory relative to a study-only condition) similar to that of explicit testing, which supports the idea that the testing effect is mainly the result of retrieval processes. In study II, I compared memory performance for covert and overt testing, and found partial support for a relative efficacy in favor of overt retrieval, compared to covert retrieval, although the effect size was small. In Study III, I further explored the distinction between different response formats (i.e., covert retrieval vs. various forms of overt testing), specifically handwriting and keyboard typing. I also examined the relative efficacy of covert versus overt retrieval as a function of list order (i.e., whether covert and overt retrieval is practiced in blocks or random order) and its manipulation within or between subjects. The results of Study III were inconclusive insofar as a relative efficacy of covert versus overt retrieval, with respect to later retention, could not be demonstrated reliably. The list order manipulations did not appear to affect covert and overt retrieval selectively. More importantly, in cases where a relative efficacy was found, the effect size was again small.

Taken together, the three studies that of thesis indicate that the benefit of testing memory appears to be almost entirely the result of retrieval processes, and that articulation alone adds very little – if anything – to the magnitude of the testing effect, at least in cued-recall paradigms. These findings are discussed in terms of their theoretical implications, as well as their importance for the development of optimal teaching and learning practices in educational settings.