Engineering design is a complex cognitive skill differing from possession of knowledge in tactical use of knowledge to achieve goals under constraints. An operational definition of a design must satisfy a set of constraints and objectives. Several published theories about the design process in terms of the criteria developed leads to the…

The results of a nonrandomized experiment indicated that the group of students who observed the static presentations of graphic images achieved slightly higher scores on the paper-and-pencil performance tests, whereas the group of students who viewed the dynamic presentations made greater gains on the mental rotation tests. (JJK)

Described are improvements for the computer efficiency of the two midpoint scan-conversion algorithms used to draw ellipses. Included are computer programs written in C programing language. (JJK)

A computerized method is described whereby a mirror image pair of drawings, simultaneously drawn by the right and the left hands, can be compared. This BASIC computer program, which is available from the authors, has applications to a variety of psychological studies. (Author/JJK)