Application Of Rapid Prototyping Technology To Improve Spatial Visualization

This paper describes spatial visualization experiments conducted at the University of Illinois Urbana-Champaign. The investigation’s focus was the use of physical models, made using rapid prototyping technology, to improve spatial visualization skills in an introductory engineering graphics course. Two studies were conducted. In the first study students enrolled in experimental lab sections had the benefit of physical models, fifty in all, of varying levels of difficulty, as an aid to visualization while engaged in the study of orthographic projections. The associated control group used traditional teaching methods, without the benefit of the physical models. The second study was designed specifically to help students identified as having poor visualization skills. The Purdue Spatial Visualization Test: Rotations (PSVT:R) was used as both a pre and post-test for all students enrolled in the graphics course. The PSVT:R pre-test results were used to select students for the second study. Half of the students identified as having scored poorly on the PSVT:R were invited to a workshop on orthographic projection. The workshop employed additional rapid prototyping models, fourteen in all, as both haptic and visual aids, in conjunction with pencil and paper exercises. The workshop attendees were the experimental group, whereas the non-attendees were the control group. Two metrics were used to evaluate the effectiveness of the physical models. The first metric was the improvement in PSVT:R scores from pre to post-test. The percentage of improvement was greater for the experimental group in both studies. This suggests that the use of physical models helps students to improve their visualization skills to a greater extent than with traditional teaching methods alone. As a second metric, scores from the sketching segment of an engineering graphics exam were used (the exam is a course requirement). The sketching segment of the exam consisted of auxiliary, missing, and section view problems. For the second study the experimental group had higher scores than the control group on the sketching segment of the exam. Thus the workshop group showed improvement in class performance as well as in visualization skills. Increased scores on this segment were not realized for the experimental group in the primary study, however. Thus the workshop option proved more beneficial than the in-class experiment, although positive feedback was received from students and instructors alike for both experiments.