The Effect of Engineering Major on Spatial Ability Improvements Over the Course of Undergraduate Studies

Transcription

1 The Effect of Engineering on Spatial Ability Improvements Over the Course of Undergraduate Studies Richard Onyancha*, Brad Kinsey Department of Mechanical Engineering, University of New Hampshire Durham, NH Abstract - Spatial ability, which is positively correlated with retention and achievement in engineering, mathematics, and science disciplines, has been shown to improve over the course of a Computer-Aided Design course or through targeted training. However, whether increases in spatial ability are obtained from freshman to senior years simply by completing courses in an engineering curriculum has not been investigated. Furthermore, whether the spatial ability of undergraduate students affects their choice of engineering major has not been studied. To provide data with respect to these questions, portions of the Purdue Spatial Visualization Test (PSVT) were administered to freshman and senior students from various engineering disciplines within a College of Engineering and Physical Science (CEPS). In addition, a self efficacy test, which was developed to assess the self confidence of students related to spatial tasks, was also administered. Data analysis showed that spatial ability, while an important parameter for retention and achievement, does not affect the choice of major for engineering students. The data indicated that the spatial ability of students in engineering majors which rely more heavily on spatial ability skills (e.g. mechanical engineering) improved more than other engineering majors. Index Terms Spatial ability, Self efficacy, Spatial visualization INTRODUCTION Spatial reasoning and visualization skills are crucial in helping engineers conceptualize the connections between objects and their representations in virtual design models. Through a survey of engineering professionals, Jensen [1] found out that spatial abilities are the most important engineering graphic skills that an individual needs to be able to succeed in the engineering profession. These skills have been positively correlated with retention and achievement in engineering, mathematics and science disciplines [2-6]. Previous research [7] has also suggested that spatial cognition is a learned skill that develops in various sequential steps. According to Contero et al [8] the importance of spatial reasoning has increased significantly from about twenty years ago with the introduction of 3D CAD applications which led to a new design paradigm of design-by-virtual models. Advances in computer technologies have led to a significant increase in the importance of spatial skills but as this need has increased, graphics courses (which aid in the enhancement of visualization skills) have been de-emphasized in most engineering curricula as was shown by Sorby [9]. The research presented in this paper investigates the effect on the spatial ability skills of students going through a four year undergraduate degree curriculum in different engineering majors in a comprehensive state university. The majors that are investigated include mechanical, electrical, civil and computer engineering. The mechanical engineering curriculum has a required 3D engineering graphics course, while the civil engineering curriculum has a course that introduces the students to the fundamentals of CAD. Another group of students who formed part of this study was enrolled in a 2-year associate degree program in civil technology which included a 2D CAD course. The electrical and computer engineering curricula do not contain explicit CAD courses. All the majors include engineering design appropriate for their discipline. Data analysis showed that while the spatial ability of engineering majors that rely more heavily on spatial ability skills (e.g. mechanical or civil engineering) improved more than other majors (e.g. electrical engineering), there was no difference in the spatial ability of incoming freshman. Thus, spatial ability does not appear to affect the choice of major and spatial ability will improve for students in majors that require strong spatial ability skills. METHODOLOGY Using parts of the Purdue Spatial Visualization Test (PSVT), and a self efficacy (SE) test developed to assess self confidence related to spatial ability tasks [10], the spatial ability of freshman and senior students from mechanical (ME), electrical (EE), computer (Comp E), and civil (Civ E) engineering were measured using web-based tests. Freshman students from the university s civil technology program (Civ Tech) were also tested as were some undeclared freshmen. The sample distribution of the students is as shown in Table 1. T1H-20

2 This investigation was done over two academic years, and the students were tested at the beginning of the fall semester. The parts of the PSVT [11] that were used consisted of 20 questions from the mental rotation of object and 20 questions from the mental rotation of perspective sections. Half of the questions in each section consisted of shaded images while the other half consisted of line (no hidden line) images. Figure 1 shows an example of a PSVT mental rotation of shaded object question while Figure 2 is an example of a mental rotation of perspective PSVT line question. The black dot in Figure 2 indicates the eye position for the new perspective. The subject would select the radio button which corresponded to the correct answer. TABLE 1 DISTRIBUTION OF SUBJECTS AMONG DIFFERENT ENGINEERING DISCIPLINES CLASS ME EE Civ E Civ Comp Tech E Undeclared Male Freshmen Female Total Seniors Male Female Total The self efficacy test is designed to assess the self confidence of a student in the performance of spatial tasks [12]. This tool is modeled after a similar protocol used to assess the self efficacy of students with respect to solving algebra problems [13]. In this test two images of an object are shown, one before and the other after a given rotation. These images are shown on the screen for three seconds. A second object is then shown in it s before rotation position and the student is asked to rate their confidence in performing a rotation similar to that shown with the first object on a seven point scale. The rating scale is a series of seven radio buttons starting with not at all confident on the extreme left to extremely confident on the extreme right. Scores on the self efficacy questions have been positively correlated to spatial ability s thus providing validation for the self efficacy test [12]. The self efficacy test consisted of 20 questions with half of them being solid images, see Figure 3, and the other half being line images as shown in Figure 4. These tests were administered to a total of 487 students (330 freshmen, 157 seniors) in the fall semesters of the 2005 and 2006 academic years. The data analysis conducted included comparing the spatial ability mean (correct) percent s from the PSVT and the SE tests for the different majors at both freshman and senior class levels to investigate any differences. Comparisons were also performed between freshmen and senior classes for each major to determine the effect of each curriculum on the spatial ability and self efficacy of the students. Because of insufficient number of females and the uneven spread of these numbers this investigation did not consider the effect of gender on spatial ability. So the data that was considered was that of the whole group (including females) and that of only males (indicated in parenthesis). The mechanical engineering freshmen were all enrolled in a 3D engineering graphics course. The civil technology students were enrolled in a two year associate degree program that included training in 2D computer graphics. FIGURE 1 SAMPLE PSVT ROTATION OF OBJECT QUESTION USING SHADED OBJECTS FIGURE 3A EXAMPLE OF A SELF EFFICACY SOLID OBJECT BEFORE AND AFTER ROTATION. SHOWN FOR 3 SECONDS FIGURE 2 SAMPLE ROTATION OF PERSPECTIVE QUESTION USING LINE OBJECTS T1H-21

3 FIGURE 3B EXAMPLE OF SECOND OBJECT SHOWN BEFORE ROTATION. STUDENT IS ASKED TO RATE THEIR CONFIDENCE (7-POINT SCALE) IN ABILITY TO PERFORM ROTATION SIMILAR TO THAT SHOWN IN FIGURE 3A computer engineering students. civil engineering (p<0.05) and civil technology (p<0.05) show a statistically significant difference when compared with mechanical engineering, but none when compared with the other groups. The self confidence (self efficacy - SE) of the freshman students in their ability to perform given object rotations is given in Table 3 and shows no statistically significant difference between the different majors except for civil technology and undeclared students when compared to the mechanical engineering group which show some statistically significant difference. This means that when the students enter their freshman year, their spatial ability and self efficacy are statistically equivalent. Excluding the female subjects from the analysis has minimal effect in most cases because of the small proportion of females to males in the different sample groups. There were some slight changes in significance when females were excluded from the analysis. The largest of these changes were observed for the civil engineering and civil technology groups which had the highest proportion of female subjects. FIGURE 4A EXAMPLE OF A LINE OBJECT BEFORE AND AFTER ROTATION, SHOWN FOR 3 SECONDS FIGURE 4B EXAMPLE OF SECOND OBJECT SHOWN BEFORE ROTATION. STUDENTS ASKED TO RATE THEIR CONFIDENCE (7-POINT SCALE) IN ABILITY TO PERFORM ROTATION SIMILAR TO THAT SHOWN IN FIGURE 4A RESULTS The mean correct PSVT percentage and the mean self efficacy (on a 7-point scale) were used as the measures of variability. Statistical significance in these measures was indicated by use of the p-value for a 2-tailed T-test. As indicated earlier the data indicated in all the data tables is for combined (males and females) and for males only (given in parenthesis). Table 2 shows the mean PSVT s for entering freshmen for the different majors viz. mechanical engineering, electrical engineering, civil engineering, computer engineering, civil technology and undeclared students. There is no statistical difference in the mean PSVT s between undeclared, mechanical, electrical and TABLE 2 COMPARISON OF MEAN CORRECT PSVT PERCENTAGE SCORES FOR FRESHMEN FROM DIFFERENT MAJORS Mean Score ME (69.83) EE (69.02) Civ E (61.56) Civ Tech (60.60) Comp E (67.71) Undeclared (66.83) ME EE Civ E Civ Tech (0.790) 0.011* (0.02*) (0.33) 0.049* (0.018*) (0.106) (0.880) (0.582) (0.790) (0.321) (0.271) (0.523) (0.697) (0.464) (0.397) * p<0.05, ** p<0.005, *** p<0.001, cf when compared with Comp E (0.898) TABLE 3 COMPARISON OF SELF EFFICACY AVERAGE SCORES (ON A SEVEN POINT SCALE) FOR FRESHMEN FROM DIFFERENT MAJORS Average ME (5.324) EE (5.106) Civ E (5.303) Civ Tech (4.806) Comp E (5.473) Undeclared (4.807) ME EE CivE Civ Tech (0.174) (0.903) (0.410) (0.012*) (0.306) (0.106) (0.455) (0.175) (0.535) (0.056) (0.045*) (0.404) (0.182) (0.999) CompE (0.114) T1H-22

4 Table 4 compares the mean correct PSVT s for seniors in mechanical, electrical, civil and computer engineering. The civil technology program is a two year associate s degree and therefore does not have seniors. The mechanical engineering group shows the highest mean PSVT that is statistically significantly different from the mean for the civil engineering group (p<0.005). While there is a difference in the mean PSVT s between mechanical and electrical engineering, this difference is only marginally statistically significant (p=0.067). The mean PSVT for the computer engineering group is lower than that for mechanical engineering though the difference is not statistically significant. Note that the sample size for computer engineering is small (N=9), therefore results may change with larger sample sizes. TABLE 4 COMPARISON OF MEAN CORRECT PSVT SCORES FOR SENIORS Mean Score p values cf p values cf p values cf ME EE Civ E ME (77.54) EE (70.57) (0.120) Civ E (70.51) 0.005** (0.025*) (0.990) Comp E (76.88) (0.916) (0.438) (0.242) Table 5 shows some interesting results on the self efficacy of seniors. While there is no statistically significant difference between the average s for electrical, civil and computer engineering, there is a significant difference between mechanical engineering and the others with the lowest average being recorded for civil engineering (Average = and p = 0.000). Comparing the mean correct PSVT performance of freshmen to those of seniors for each major showed some interesting results as can be seen in Table 6. Mechanical engineering majors showed a statistically significant (p=0.001) increase in the mean PSVT s from freshman to senior year while civil engineering majors indicated only a marginally significant increase (p=0.056). Electrical and computer engineering did not show any statistically significant change in their mean PSVT s. The self efficacy of the mechanical engineering group improves significantly (p=0.01) from the freshman to senior year as seen in Table 7. Civil engineering students showed a marginally significant difference (p=0.051), while electrical and computer engineering groups did not show any statistically significant improvement. TABLE 5 COMPARISON OF SELF EFFICACY AVERAGE SCORES FOR SENIORS FROM DIFFERENT MAJORS Average ME EE Civ E Score ME (5.618) EE (5.177) 0.046* (0.051) Civ E (4.899) 0.000*** (0.000***) (0.195) Comp E (4.919) (0.055) (0.509) (0953) TABLE 6 COMPARISON OF PSVT MEAN SCORES FOR FRESHMEN AND SENIORS IN THE DIFFERENT MAJORS T1H-23 Freshman mean Senior mean p values ME (69.83) (77.54) 0.001*** (0.002***) EE (69.02) (70.57) (0.762) Civ E (61.56) (70.51) (0.045*) Comp E (67.71) (76.88) (0.257) * p<0.05, ** p<0.005, *** p<0.001 TABLE 7 AVERAGE SELF EFFICACY SCORES COMPARISON BETWEEN FRESHMAN AND SENIOR CLASSES Freshman Senior average average p values ME (5.324) (5.618) 0.010* (0.023*) EE (5.106) (5.177) (0.782) Civ E (5.303) (4.899) (0.051) Comp E (5.473) (4.919) (0.221) * p<0.05, ** p<0.005, *** p<0.001 DISCUSSION Spatial ability (as measured with the PSVT test) is not a factor in the choice of engineering major for entering freshmen but it improves during the course of a four year engineering program, in particular for majors that require strong spatial ability skills (e.g. mechanical and civil engineering). The mean PSVT s for almost all entering freshmen are about the same with no statistically significant difference between the different majors. The only exception to this is civil engineering (p=0.01) and civil technology (p=0.049) when compared to mechanical engineering. The greatest improvement in mean PSVT s is seen in mechanical (69.26 to 77.37, p=0.001) and civil (60.69 to 68.70, p=0.056) engineering majors. These majors require many spatial visualization techniques and tools such as engineering drawing and drafting, computer aided design and modeling. Electrical and computer engineering showed modest increases in the mean PSVT s that were not statistically significant. This may be due to the nature of these programs in that they don t have a heavy reliance on spatial visualization tools, similar to those used in the tests, in their teaching learning process. The self efficacy of entering freshmen shows no statistically significant difference between the different majors. An analysis of the self efficacy mean s for the

5 senior classes indicates a very clear and statistically significant difference between electrical (mean 5.127, p<0.05) and civil engineering (mean 4.957, p=0.000) on the one hand and mechanical engineering (mean 5.590) on the other. Mechanical engineering showed the only statistically significant improvement in the self efficacy of students from freshman to senior year from to (p<0.05) while civil engineering (5.356 to 4.957, p=0.05) actually indicated a statistically significant decrease. The decrease in self efficacy seen for the civil engineering group did not correlate with the statistically marginally significant improvement in spatial ability. The self efficacy of the electrical and computer engineering groups decreased slightly but these decreases were not statistically significant. It should be noted that not all of the freshmen who were administered the tests will remain in the given major due to attrition. Thus, the results may be affected by this. Future research will track students throughout their college careers to verify the results presented here. CONCLUSION The effect of engineering major on spatial ability and self efficacy changes over the course of undergraduate studies were investigated. Overall the spatial ability and self efficacy were equivalent for freshman students regardless of the engineering discipline enrolled. Furthermore, it was found that those majors that teach or use many spatial visualization tools and techniques such as CAD software had the greatest spatial ability improvements over a four year matriculation period. Mechanical engineering showed the most significant improvement in mean PSVT s from to (p=0.001) followed by civil engineering with mean PSVT s increasing from to (p=0.056). The improvements for the electrical and computer engineering groups were only marginal and not statistically significant. The average self efficacy s for mechanical engineering students increased significantly from freshman to senior year while those for the other groups decreased. The decrease in self efficacy for the civil engineering group, from to was statistically significant with p=0.05. The reason for the marginal increase in mean PSVT s and a decrease in the average SE s for the electrical, computer and civil engineering groups may be due to the nature of the objects and rotations that are used in the tests which tended to be more mechanical than any of the other disciplines. [2] Coleman, S.L. and A.J. Gotch, Spatial Perception Skills of Chemistry Students, Journal of Chemical Research, Vol. 75, No. 2, 1998, pp [3] Carter, C.S., M.A. LaRussa, and G.M. Bodner, A Study of Two Measures of Spatial Ability as Predictors of Success in Different Levels of General Chemistry, Journal of Research in Science Teaching, Vol. 24, No. 7, 1987, pp [4] Pallrand, G.J. and F. Seeber, Spatial Ability and Achievement in Introductory Physics, Journal of Research in Science Teaching, Vol. 21, No. 5, 1984, pp [5] Lord, T.R., Enhancing Learning in the Life Sciences through Spatial Perception, Innovative Higher Education, Vol. 15, No. 1, 1990, pp [6] Sorby, S., Improving the Spatial Skills of Engineering Students: Impact on Graphics Performance and Retention, Engineering Design and Graphics Journal, Vol. 65, No. 3, 2001, pp [7] Piaget, J., Inhelder, B., The Child s Conception of Space, New York: The Norton Library, 1967 [8] Contero, M., Naya, F., Company, P., Saorín, J.L., "Learning Support Tools for Developing Spatial Abilities in Engineering Design", International Journal of Engineering Education, Vol. 22, No.3, 2006, pp [9] Sorby, S.A., A Course in Spatial Visualization and its Impact on the Retention of Female Engineering Students, Journal of women and minorities in science and engineering, vol. 7, No.2, 2001, pp [10] Kinsey, B.L., Towle, E., Hwang, G., O Brien, E., Bauer, C., Effect of Object and Rotation Type on Self Efficacy and Spatial Ability Test Results, Submitted to the Journal of Engineering Design Graphics, [11] Guay, R., Purdue Spatial Visualization Test: Rotations, Purdue Research Foundation, West Lafayette, IN, 1977 [12] Kinsey, B.L., Towle, E., O Brien, E., and Bauer, C., Analysis of Selfefficacy and Ability Related to Spatial Tasks and the Effect on Retention for Students in a College of Engineering and Physical Science, Submitted to the International Journal of Engineering Education, 2006 [13] Schunk, D.H., Effect of Effort Attributional Feedback on Children s Perceived Self-efficacy and Achievement, Journal of Educational Psychology, vol. 74, 1982, pp ACKNOWLEDGMENT We would like to gratefully acknowledge the National Science Foundation for their support through grant No.EEC for this work. REFERENCES [1] Hensen, J.J., The Impact of Computer Graphics on Instruction in Engineering Graphics, Engineering Design Graphics Journal, vol. 50 No.2, 1986, pp T1H-24