COGNITIVE LOAD AND MENTAL ROTATION - STRUCTURING ORTHOGRAPHIC PROJECTION FOR LEARNING AND PROBLEM-SOLVING

Cognitive load theory was used to generate a series of three experimen ts to investigate the effects of various worked example formats on lea rning orthographic projection. Experiments 1 and 2 investigated the be nefits of presenting problems, conventional worked examples incorporat ing the final 2-D and 3-D representations only, and modified worked ex amples with several intermediate stages of rotation between the 2-D an d 3-D representations. Modified worked examples proved superior to con ventional worked examples without intermediate stages while convention al worked examples were, in turn, superior to problems. Experiment 3 i nvestigated the consequences of varying the number and location of int ermediate stages in the rotation trajectory and found three stages to be superior to one. A single intermediate stage was superior when near er the 2-D than the 3-D end of the trajectory. It was concluded that ( a) orthographic projection is learned best using worked examples with several intermediate stages and that (b) a linear relation between ang le of rotation and problem difficulty did not hold for orthographic pr ojection material. Cognitive load theory could be used to suggest the ideal location of the intermediate stages.