Applied tests of engineering design skills: Visual thinking characterization, test development and validation

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 these skills. We have already reported on the contents and rationale for divergent thinking test, as well as, on data collection and statistical analysis for it. This paper focuses similarly on the efforts related to the visual thinking and spatial reasoning in engineering context. It is designed to evaluate six measures: visual comprehension including perceptual speed, visual memory, 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 300 samples, engineering students and a smaller number of practicing engineers. The test is shown to be reliable (Cronbach alpha less than .05 and only 2 eigenvalues greater than 1).