Elaborations in Expository Text Impose a Substantial Time Cost but Do Not Enhance Learning

Abstract

Textbook passages commonly include elaborations (details supporting main ideas) with the assumption that elaborations will improve learning of the main ideas. However, elaborations increase text length, which subsequently increases the reading time of that text. These observations lead to the two focal questions of interest in the current study: What is the time cost imposed by including elaborations within textbooks? Does the benefit of elaborations for enhancing memory for main ideas outweigh this time cost? In three experiments, students studied elaborated versus unelaborated versions of psychology textbook passages. Two days later, students completed final tests, including cued recall for main ideas and comprehension tests. In all experiments, we found a substantial cost in terms of increased reading time for the elaborated text but no evidence of increased memory for main ideas to offset this cost. To facilitate further interpretation of the similar test performance observed for elaborated versus unelaborated texts, experiment 2 ruled out functional floor or ceiling effects and established that both text versions enhanced learning (but did so to a similar extent). These results indicate that elaborations embedded within textbook passages may not facilitate learning and that unelaborated texts may be more efficient than elaborated texts.