Abstract

Science standards call for students to develop skills in designing their own investigations. However, this is a complex task that is likely to overload the working memory capacities of students, therefore requiring scaffolding. This study investigated the effects of a computerized scaffold for student-designed experiments. Students (N = 102) used the computer program to individually design an experiment during the third week of their high school general chemistry course. Students were randomly assigned to one of four software versions to determine the effects and interaction effects of backwards-design scaffolding and reflective prompts on laboratory report scores. Scaffolding the students in a backwards-design process lead to significantly higher student performance scores for all students when they were not provided with reflective prompts (p = 0.01). For students labeled as academically advanced by their eighth grade science teacher, backwards design increased student performance scores with or without reflective prompts (p = 0.002). Using reflective prompts had no effect on advanced students. The use of multiple reflective prompts caused the effect of the backwards-design scaffolding to disappear with lower-level students.