Do Spatial Abilities Impact The Learning Of 3 D Solid Modeling Software?

With the prolific use of 3-D solid modeling packages, should engineering graphics courses designed to improve spatial visualization skills continue to be an important foundation topic in engineering education? Does a person’s spatial ability influence their ability to learn and use 3D solid modeling packages? In the fall of 2005, a study was undertaken at Michigan Technological University to answer these questions. Two different tests were administered at the beginning of an introductory engineering course to determine the students’ level of spatial ability: the Purdue Spatial Visualizations Test: Rotations and the Mental Cutting Test. In the introductory engineering course, students receive five class periods of instruction in engineering graphics (isometric sketching, orthographic projection, rotations, and other topics) and three class periods of instruction in a 3-D solid modeling package. Some of the students received instruction in engineering graphics before learning 3-D modeling software, and some after. Upon completion of the 3-D solid modeling module, students filled out a questionnaire to assess their ease of learning and using the modeling software. The questionnaire was related to a common assignment and asked students to track the amount of time they spent completing the assignment, how much help they needed, and how difficult they found the assignment to be. Students were also asked to compare their ability to use the software and their ease in learning the software with their teammates’. Correlation analyses were performed to determine if a person’s spatial ability is correlated to his/her ability to effectively learn to use the 3-D solid modeling package and to determine if spatial visualization instruction prior to 3-D modeling instruction improves student success with learning the modeling package. The findings from this study are presented in this paper. Introduction In a research study conducted at Michigan Technological University in 1997, it was shown that the mere act of working with 3-D computer models in a solid modeling environment does not develop visualization skills 1 . A 1994 study by Norman 2 found that a person’s spatial visualization skills were the most significant predictor of a person’s success in interacting with a computer interface to perform database operations. A 1999 study by Sorby 3 found little correlation between spatial abilities and the ability to work with 2-D drafting software, but found an apparent correlation between spatial abilities and the ability to interact with a computer in a 3D modeling environment. However, in that previous study there were some potential errors in data-gathering and in survey instrument design. Further, at the time, graphics at Michigan Tech was taught as a stand-alone course whereas it is now taught so that it is integrated with other topics. Between 1999 and the present, the 3-D graphics package used at Michigan Tech has also changed from I-DEAS to Unigraphics UGNX3. For these reasons and to determine if the results were repeatable, it was decided to conduct a modified study on 3-D spatial skills and their relationship to learning 3-D modeling software under the new system. Present Study To assess the influence a person’s spatial ability has on their ability to learn and use a 3-D solid modeling package, a study was undertaken at Michigan Tech in the fall of 2005. This study P ge 11493.2 involved students enrolled in the first of two introductory engineering courses, ENG1101. Students were pre-tested at the beginning of the course with two different tests designed to assess their spatial abilities. These tests included the Purdue Spatial Visualization Test: Rotations (PSVT:R) 4 and the Mental Cutting Test (MCT) 5 . In ENG1101 students receive instruction in both sketching-based engineering graphics and 3-D solid modeling. Five 1.5-hour class periods are devoted to engineering graphics via sketching; the topics covered include isometric sketching, object transformations, and orthographic projections. It should be noted that additional graphics/modeling instruction is included in the second introductory course; however, their initial exposure to these topics is in ENG1101. Solid modeling is introduced in three or four class periods using Unigraphics UGNX3. The topics in 3-D modeling that are covered in the course include computer-based 2-D sketching and constraints, profile extrusion, combining solids, and creating a drawing layout. Of the twelve sections of ENG1101 (n=627) taught in the fall of 2005, four sections (n=178) covered solid modeling prior to sketching, while the remaining eight sections (n=449) covered solid modeling after sketching. Due to the academic and holiday calendar four days were devoted to 3-D modeling in the four sections covering 3-D modeling first, while only three days were spent on 3-D modeling in the eight sections that covered the 3-D modeling after sketching. Upon completion of the solid modeling sessions, students were given a common homework assignment that required them to model a part and create an engineering drawing of that part. To assess their ability to learn and use a 3-D modeling program, the students were asked to complete a questionnaire regarding their ease in completing the assignment. Assuming that our undergraduate student teaching assistants are representative of the students enrolled in the course, the questionnaire was pilot tested with teaching assistants prior to implementation with the student-subjects. The questionnaire consisted of sixteen questions and is shown in Figure 1. In accordance with Michigan Tech’s policy regarding the use of human subjects in research projects, the completion of the survey was strictly voluntary. Of the 627 students enrolled in the course, 329 students completed and returned the questionnaire.