development and assessment of a course for enhancing the 3-D spatial visualization skills of first year engineering students, The

Journal of Engineering Education, Jul 2000 by Sorby, Sheryl A, Baartmans, Beverly J

ABSTRACT

In January 1993, we received NSF funding to develop a pre-graphics course for freshman engineering majors who are weak in 3-D spatial visualization skills. A text and computer lab exercises utilizing I-DEAS software were written specifically for this course. The course is 3-credits (quarter system) with two hours of lecture and two hours of computer lab each week. It was offered at Michigan Technological University (MTU) for the first time during the 1993 Fall term and has been offered each fall since that time. The objective ofthe course is to provide the prerequisite spatial skills needed by students to succeed in their subsequent engineering graphics courses. Assessment for the course has been continuous. Recently, a six-year longitudinal study was conducted to determine the overall success of this project. This paper will describe the project and the assessment findings from the longitudinal study.

I. INTRODUCTION

Visualization of problems is critical for success in engineering education. In most cases, it is an essential ingredient for student understanding. It is recognized that the ability to visualize is an important tool required of engineers in order to function effectively." In addition to the traditional visualization tasks associated with engineering design, enhanced visualization skills are necessary to function in this new age of Computer Aided Design. In fact, Normans found that a person's spatial ability is the primary factor that explains differences in performance in fully utilizing computer-based technology. Unfortunately, at a time when visualization skills are increasingly important to students, engineering graphics (the primary course where students first learn visualization concepts) has been de-emphasized, and in many cases, dropped from engineering curricula altogether.6

A. The Development of 3-D Spatial Ability

According to Piagetian theory, an individual acquires spatial visualization ability through three distinct stages of development! In the first stage, children learn topological spatial visualization where they are able to discern an object's topological relationship with other objects-i.e. how close the objects are to one another, an object's location within a group of objects, the object's isolation, etc. In the second stage of development, projective representation is acquired. At this stage, people are able to conceive what an object will look like from different perspectives. In the final stage of spatial visualization development, a person learns to combine projective abilities with the concept of measurement.

There are several standardized tests available to measure a person's ability across the first two stages of spatial development. For example, the Purdue Spatial Visualization Test: Rotations (PSVT:R) was devised to test a person's ability at the second stage of spatial development.8 A sample problem from the PSVT:R is shown in figure 1. This testing instrument was used throughout this project to identify students who have weaknesses in spatial visualization skills and partially to assess the impact of the experimental course.

The Mental Rotation Test (MRT)9 is another test designed to assess a person's ability to visualize rotated solids. It consists of 20 items where students are shown a criterion figure on the left and asked to identify which two of four given choices represent the same object after rotation in space. There are 40 points possible on the MRT and a sample problem is shown in figure 2. The Mental Cutting Test (MCT) was first developed as part of a university entrance examination in the USA and consists of 25 items. For each test problem, students are shown a criterion figure that is to be cut with an assumed plane. They must choose the correct resulting cross-section from among five alternatives. A sample problem from the MCT is shown in figure 3.

The Differential Aptitude Test: Space Relations (DAT:SR)," consists of 50 items. The task is to choose the correct 3-dimensional object from four alternatives that would result from folding the given 2-dimensional pattern. In one study,'2 it was found that a student's score on the DAT:SR was the most significant predictor of success in an engineering graphics course when compared to three other spatial visualization tests that were given (including the MCT). A sample problem from the DAT:SR is shown in figure 4.

B. Background Research at MTU

It is well-documented that the 3-D visualization skills of women lag behind those of their male counterparts..3,13-16 Studies conducted at MTU by Gimmestad (now Baartmans) support these findings. A course such as the one described in this paper can help women students address a deficiency in their background so that they are more likely to succeed in their engineering studies (and in particular their design graphics courses). In fact, Hsi et aP found that a Saturday tutorial session on spatial strategy instruction significantly improved the performance of men and women students in an engineering graphics course.