Coordinate Axes And Mental Rotation Tasks: A Dual Coding Approach

During the 1997 Fall semester at North Carolina State University, a study was conducted to determine the effectiveness of adding coordinate axes to a mental rotations task. Eighty-one undergraduate students enrolled in introductory graphic communications courses completed a computer version of the Purdue Spatial Visualization Test Visualization of Rotations (PSVT). The instrument was used to record student responses and response times as well as information on gender, current major, number of previous graphics courses completed, and method used to solve the test items. The theoretical framework of the study is based on Paivio’s dual-coding theory [1]. Coordinate axes were added to a portion of the PSVT for the experimental group to determine if the axes provided contextual cues necessary to improve scores and response times. The researcher hypothesized that coordinate axes would provide verbal cues that could be coded along with nonverbal information to improve mental rotation efficiency. The additional coordinate axes slightly (but not significantly) improved scores on the PSVT, but not response times. Introduction Spatial ability has been of interest to people in many disciplines. It has been shown to be related to success in chemistry [2], geometry [3], and technical graphics [4]. Researchers in these fields have been concerned with devising ways to increase the spatial abilities of their students. The problem is spatial ability has been defined many different ways. McGee [5] defines spatial ability in terms of two factors: spatial visualization and spatial orientation. Spatial visualization requires the individual to mentally transform a perceived object (mentally rotate, twist, or invert). Spatial orientation requires the individual to remain unconfused when a pattern of objects has been rearranged. Since spatial ability is defined in many ways, it is also true that tests designed to measure spatial ability are equally as diverse. Research has shown that the Purdue Spatial Visualization Test Visualization of Rotations [6] measures spatial visualization ability. Information-processing theory provides an explanation for how spatial information is processed. The dual-coding model [7] offers some explanation for differences in processing strategies. Humans process information mentally through two systems. The verbal system handles abstract information and processes it in a sequential, successive manner. The nonverbal system handles concrete information and processes it in a synchronous, simultaneous manner. The nonverbal system handles mental rotation tasks more efficiently than the verbal system, however, the main emphasis of Paivio’s theory is that information processed or coded in both systems can be retrieved and manipulated more readily. P ge 368.1 The purpose of the study was to determine whether the presence of coordinate axes in a test of spatial visualization ability affects scores and response times on a mental rotations task for students enrolled in undergraduate introductory graphic communications classes. Coordinate axes were added to the Purdue Spatial Visualization Test Visualization of Rotations (PSVT) to determine whether the presence of the axes was a sufficient contextual cue for improving scores and response times. The major research question set up for this study was: Does the contribution of frames of reference (coordinate axes) to mental rotations tasks affect scores on tests of spatial visualization ability? The following nine research hypotheses guided the modification of the testing instrument, the selection of the sample, additional data collected from the examinees, and analysis of the data: 1. For the experimental group, the mean score will be significantly higher on Part 2 of the PSVT (coordinate axes present) than on Part 1 (no axes). 2. There will be no significant difference between the mean scores on Parts 1 and 2 of the PSVT for students in the control group. 3. The mean score on Part 2 of the PSVT for the experimental group will be significantly higher than the mean score for the control group. 4. For the experimental group, the mean response time will be significantly lower on Part 2 of the Purdue Spatial Visualization Test-PSVT (coordinate axes present) than on Part 1 (no coordinate axes). 5. There will be no significant difference between the mean response times on Parts 1 and 2 of the PSVT for students in the control group. 6. The mean response time on Part 2 of the PSVT for the experimental group will be significantly lower than the mean response time for the control group. 7. The mean score for males will be higher than the mean score for females on Part 1 of the PSVT (Part 1 no coordinate axes present should favor a holistic approach). 8. There will be no difference in mean scores between males and females on Part 2 of the PSVT for the experimental group (the presence of coordinate axes should allow success for both holistic and analytical approaches). 9. The mean response time for males will be lower than the mean response time for females on Parts 1 and 2 of the PSVT (the analytic approach requires more processing time). Procedures During the summer of 1997, two computer versions of the Purdue Spatial Visualization Test Visualization of Rotations were developed by the researcher using Macromedia’s Authorware 3.5 on Microsoft Windows95 TM personal computers. One version was used by the subjects in the control group while the other version was used by subjects in the experimental group. The initial 30 items of each test were identical to the 30 items of the paper/pencil version of the PSVT. The second 30 items of the control group version of the test were identical to the first 30 items except for the random assignment of the correct solution. The second 30 items of the experimental group version of the test were identical to the second 30 items of the control group version except that coordinate axes were added to the first and second stimulus objects for each item (see Figure 1). The computerized PSVT was pilot tested during the second summer session of 1997 to check the reliability and smoothness of data collection procedures. P ge 368.2 During the second week of classes for the 1997 Fall semester, the class rolls for all introductory courses in Graphic Communications were used to select a random sample of 150 undergraduate students. The researcher visited each introductory class and invited the 150 students to participate in the study. One hundred thirty-three students signed up to participate in the study as a result of the researcher visiting the introductory classes. Both the control and experimental groups were administered Part 1 of the PSVT. After a short rest period, Part 2 of the PSVT was administered. At the end of the test, students were asked to respond to several demographic questions.