Folding a fish, making a mushroom: The role of diagrams in executing assembly procedures

Three experiments examined the role of step-by-step and final-state diagram s in supporting object assembly. A total of 180 college students made origa mi objects from instructions consisting of text only, text plus a final-sta te (completed-object) diagram, or text plus step-by-step and final-state di agrams. in Experiments 1 and 2, construction accuracy in the final-diagram condition was comparable to that in the step-by-step condition when the obj ects required few assembly steps, but it was comparable to that in the text -only condition when many steps were required. Experiment 3 independently m anipulated the number of assembly steps and the ease of seeing the steps in , or inferring them from, the final diagram. The results indicated that the ease of extracting the steps from the fmd diagram was the primary causal v ariable in the interaction with instructional condition. We interpret these results in terms of mental model construction and working memory load.