Do long textbook passages support student learning of main ideas?


Reference: Daley, N., & Rawson, K. A. (2018). Elaborations in Expository Text Impose a Substantial Time Cost but Do Not Enhance Learning. Educational Psychology Review, 1-26.

Have you ever wondered why textbook chapters are so long? Sitting at my desk trying to slog through an assigned chapter, I remember asking myself this question. Given the length of that textbook chapter, my professor obviously did not expect me to memorize every word — they wanted me to remember the main ideas. But those main ideas only constituted a small portion of the chapter. Most of the remaining information consisted of details that further described, illustrated, or explained the main ideas (i.e., elaborations).  Was my time well spent reading all of these elaborations? For an answer to this question, I turned to the existing research but came up empty-handed. So, along with my graduate advisor, Dr. Katherine Rawson, we set out to investigate this question.

Method and Results

To address this issue, we conducted three experiments in which students studied passages from undergraduate-level psychology textbooks. These passages either contained just the information that students needed to know (i.e., the main ideas) or the information along with elaborations (e.g. examples, additional details, and description).  Students read either an electronic passage (Experiments 1 and 2) or a printed version of the passage (Experiment 3). Two days later, they returned to the lab and completed tests designed to assess their learning of the main ideas. To assess their memory for the main ideas, they completed a cued recall test where they wrote down specific information about the key-term definitions. Additionally, to assess their understanding of the main ideas, they completed a comprehension test where they identified these key terms in specific scenarios.

As we expected, students spent more time reading when the passage contained elaborations. In fact, across all experiments, students spent approximately double the time reading the passage with main ideas and elaborations versus just the main ideas. Was this additional time well spent?  Probably not. Our results provide no evidence that reading the elaborations resulted in greater learning of the main ideas: Students had similar memory and understanding regardless of which version of the passage they read.

(2) Similar performance was observed on memory and comprehension posttests for the elaborated versus unelaborated version of the texts. However, students spent about twice the time reading the elaborated versus the unelaborated versions.

Takeaways for Researchers

 Should textbook writers ditch elaborations altogether? Not based on the results of our study alone. Keep in mind, we conducted these three experiments at a single university with undergraduate students and used texts on two topics from the subject of psychology (memory and language). Although we hope that these experiments provide a useful starting point for future research, many questions remain about the usefulness of elaborations. Do elaborations support learning in younger students? Do elaborations support learning of other subjects? Can elaborations support learning when the text clearly indicates the main ideas (e.g., bolded or highlighted)? These questions, and many others, are important next steps for interested researchers.  

Takeaways for Students

What can current students learn from these results? If you are a student who has invested time in reading texts with elaborations, you may find these results disheartening. But there’s no need to burn your $200 textbook. Instead, these results suggest one way to more efficiently use textbooks to reach your learning goals: by focusing on the main ideas. Instead of trying to slog through the whole chapter, try focusing on the summaries of the main ideas that are commonly provided in textbooks. This strategy will take less time and still allow you to learn the main ideas.  

Images: (1) Features image from (2) Figure 4. Experiment 2. Image reprinted from “Elaborations in Expository Text Impose a Substantial Time Cost but Do Not Enhance Learning,” by N. Daley and K. A. Rawson, in press, Educational Psychology Review. Copyright 2018 by Springer Science+Business Media, LLC, part of Springer Nature. Reprinted with permission.