Students' transition from an engineering model to a science model of experimentation

This study investigates the hypothesis that when children are engaged in science experiments, the goal of which is to understand relations among causes and effects, they often use the engineering model of experimentation, characterized by the more familiar goal of manipulating variables to produce a desired outcome. Sixteen fifth- and sixth-graders worked on two experimentation problems consistent with the engineering and science models, respectively. The context in which these problems were framed was also varied, to encourage adoption of either an engineering or science model. Over six 40-min sessions, the group achieved significant increases in the percentages of inferences about variables that were both correct and valid. Improvement was greatest for those who began with the engineering problem and then went on to the science problem. The science model was associated with broader exploration, more selectiveness about evidence interpreted, and greater attention to establishing that some variables are not causal. The findings suggest that research on scientific inquiry processes should attend not only to the science content students are reasoning about, but also to their beliefs about the goals of inquiry.