The Effect of Instructional Explanations on Learning From Scientific Texts

Abstract This study explored the influence of offering different instructions to undergraduate students prior to their learning an expository text on evolutionary biology. Participants were asked to either explain, summarize, or listen to another's explanation or summary of Darwin's theory of evolution through natural selection. Three conditions were compared: In Condition 1, students were told to study the text because they were going to teach the contents of the text to their partner by either explaining or summarizing (these are referred to as the teach through explanation or summary conditions). In Condition 2, 2 different groups of participants were told to study the identical material on evolution and either explain or summarize the contents of the text aloud to the experimenter following the study period. However, they were only told to do so after they were finished studying for themselves. These are referred to as the explain or summarize to self conditions. In Condition 3, 2 different groups did not read the text for themselves. They were told that their partner was preparing to teach them a text on evolution and that they should listen carefully to their partner's explanation or summary because they would be asked some questions afterwards. These 2 groups are referred to as the hearers (50% listened to an explanation and 50% listened to a summarization). Overall, explainers outperformed summarizers on a far transfer task dealing with evolution. Moreover, the teach through explaination condition had the strongest effect on students' learning from text as measured by their performance on (a) an explanation-summary task, and on (b) evolutionary near and far transfer problems.