Abstract:
In the field of multimedia learning, the multimedia effect, which states that adding pictures to text is beneficial to learning, is a well-established effect. Although many empirical studies have shown that pictures are beneficial to learning, it is still unclear why they are beneficial to learning. In this dissertation, two theoretical accounts that explain the multimedia effect have been contrasted to see which account explains the multimedia effect best: the Cognitive Theory of Multimedia Learning (CTML) and the account of computational offloading. CTML explains the multimedia effect by arguing that learning from text and pictures yields a richer mental representation than learning from text only. In contrast, the account of computational offloading explains the multimedia effect by arguing that information processing in working memory is facilitated when learning with text and pictures compared to learning with text only.
In this dissertation, three experiments are reported that tested 1) whether the beneficial effect of pictures depends on the amount of visuo-spatial information processing that is required by a certain type of task (i.e., conceptual, causal, procedural), 2) whether information processing in working memory differs between types of tasks, and 3) whether information processing in working memory differs between processing text only or processing text and pictures. The results did not unanimously support any of the theoretical accounts. Therefore, it was argued that a theoretical account that combines both explanations of the multimedia effect, stating that pictures yield a richer mental representation and that pictures are under certain circumstances computational offloading, seems to be most likely. However, it is noted that further research is needed that continues to address the question why pictures are beneficial to learning, taking the reported limitations and strengths into account.