Analysis of Causes of Errors in the Mental Cutting Test - Effects of View Rotation

Since 1990, the Mental Cutting Test (hereafter MCT) has been widely used to measure spatial abilities in relation to graphics curricula. It became clear that the evaluation by MCT mainly reflects the ability to recognize the solid from the perspective drawing and the ability to consider the problems analytically. Most of the subjects who made low scores on the MCT, however, could not imagine the space itself, when they observed projection drawings. They seemed to have rather vague criteria for judging depth. In this respect, if the process of rotating the test solids is added to the MCT and given subjects discretionary views of the test solid, it might be possible to promote a better sense of recognizing a 3-D object and forming correct images. In this study, the Rotated-View MCT (hereafter RV-MCT) using a computer system in which subjects were able to rotate the problem solid on the horizontal plane within the limits +180 ◦ and −180 ◦ using a horizontal scroll bar was devised. The RV-MCT consists of 9 problems together with 2 exercises all of them were extracted from standard MCT, including both easy and difficult problems. The RV-MCT was conducted to twenty-nine female students. None of the subjects had taken any previous course on graphics. The standard MCT was conducted to another 31 subjects in the same period in order to provide reference data. The main results were as follows; (1) the mean score of the RV-MCT was significantly high compared to that of standard MCT; (2) subjects did not always make correct answers even when they could observe the