Applied tests of design skills-part ii: Visual thinking

A number of cognitive skills relevant to conceptual design have been previously identified: divergent thinking, visual thinking, spatial reasoning, qualitative reasoning, and problem formulation. A battery of standardized test has been developed for each of these skills. This is the second paper in a series of papers on testing individual skill level differences in engineers and engineering students. In the first paper, we reported on the theoretical and empirical basis for divergent thinking test, as well as, on test formulation, data collection, norming studies, and statistical validation of that test. This paper focuses similarly on the efforts related to the visual thinking and spatial reasoning in engineering context. We have decomposed visual thinking into six categories: visual comprehension including perceptual speed, visual memory (that is, the visual memory system), visual synthesis mental image manipulation/transformation, spatial reasoning, and graphical expression/elaboration. We discuss the theoretical basis of a comprehensive test for engineers, test composition, trial runs, and computation of reliability measures. The alpha version was given to a small set of subjects to determine clarity of the questions and gauge difficulty level. The beta version was used for norming and test validation from over 500 samples that included engineering students and a smaller number of practicing engineers. Construct validation was achieved through basing the construction of our instrument off other well-known measures of visual thinking, while content validity was assured through thoroughly sampling the domain of visual thinking and including a variety of items both pertinent and specific to the engineering design process. The factor analysis reveals that there are possibly two eigenvalues above 1.0, an indication that it is a stable and accurate instrument. We emphasize that these tests are not just dependent on native abilities, but on education and experience; design skills are teachable and learnable.