The spacing effect, working memory resource depletion, and levels of element interactivity

This thesis investigates the relationship between the spacing effect, levels of element interactivity, and working memory resource depletion. Spaced practice is aimed at generating a spacing effect that is easy to implement in classrooms and, if effective, could potentially lead to considerable gains in student achievement. This research area has attracted much attention in different areas, such as second language learning (vocabulary and grammatical learning) and motor skills (Cepeda et al., 2006; Kim & Webb, 2022). Also, there are various types of theoretical explanations developed to account for the spacing effect, like the study-phase retrieval hypothesis and desirable difficulty (Toppino et al., 2018; Bjork, 1994). However, several questions remain.

First, the impact of the spacing effect on mathematics performance is unclear, as the existing literature provides inconsistent results. Second, previous research on the spacing effect has focused on the types of learning materials and subject areas. Yet, it is unclear whether the learners' knowledge level and the difficulty of the materials (element interactivity) influence the spacing effect. Lastly, some aspects of the spacing effect remain unexplained by existing theoretical accounts. Therefore, within cognitive load theory framework (Sweller, 2020; Chen et al., 2018), a new explanation called the working memory resource depletion hypothesis has been developed to address these gaps. These hypotheses, which I will explore in this thesis, might advance our understanding of the spacing effect. The research questions of this thesis are:

1.

How does the level of element interactivity influence the spacing effect and working memory resource depletion?

2.

To what extent does working memory resource depletion account for the spacing effect?

3.

How does learners’ prior knowledge impact the spacing effect and working memory resource depletion?

This thesis addresses the above research questions within the context of the spacing effect and cognitive load theory. The first part of the thesis examined how working memory resource depletion could explain the spacing effect in novices and more knowledgeable learners. The findings provided evidence of the spacing effect and working memory resource depletion in novices. However, both effects disappeared as learners' knowledge levels increased, suggesting that knowledge level could be a potential moderator in the spacing effect and working memory resource depletion. The second part of the thesis examined how different factors—such as the complexity of the learning materials and the learners' knowledge level—influenced the spacing effect and the depletion of working memory resources. A classroom experiment did not find a relationship among the levels of element interactivity, the spacing effect, and working memory resource depletion in novices but identified a possible trend (not statistically significant) of better performances in the spaced group compared to the massed group in the post-test and working memory test. Another experiment found no statistically significant effect on the working memory test or the post-test for more knowledgeable learners, regardless of the level of element interactivity in the learning materials. As predicted, there was no relationship between the spacing effect and working memory resource depletion when the materials were low in element interactivity (less complex), regardless of learners' knowledge level. However, there was also no relationship between the spacing effect and working memory resource depletion when materials were high in element interactivity (more complex) as well, which was inconsistent with previous literature. A final experiment with the most difficult learning materials revealed a spacing effect, but no evidence of working memory resource depletion in novices, regardless of the element interactivity levels. This finding was also inconsistent with previous literature. The results revealed that learners might experience mental rehearsal when rehearsing learning materials during the spacing gaps, revealing a possible new direction in future research. The final part of the thesis involved a meta-analysis of the spacing effect on mathematics achievement to find out how spaced practice impacts mathematics achievement. I found a significant improvement in mathematics achievement, with education level as a significant possible moderator.

In conclusion, this thesis demonstrated that working memory resources were more likely to become depleted in novices, but not in more knowledgeable learners when engaging with materials high in element interactivity. In contrast, this depletion did not occur with materials low in element interactivity. Additionally, the spacing effect was evident with materials high in element interactivity, but it was not evident with materials low in element interactivity. However, more studies are needed to further explore the influence of learners' prior knowledge levels and the difficulty of learning materials on the spacing effect. Similarly, more research is needed to understand how the spacing effect impacts mathematics achievement. Lastly, the results of the meta-analysis suggested that spaced practice could effectively enhance mathematics performance. This indicates that educators might consider incorporating spaced practice into mathematics lessons, especially in primary schools, as has been successfully done in other areas, such as second language learning. The findings of this thesis underscored the importance of further research in how spaced practice influence mathematics performance.