Random figures and mirror images with variable complexity,size, and orientation in Applesoft BASIC

An algorithm is described for generating random figures of variable complexity, and programs are described for generating libraries of the figures and their mirror images encoded as Applesoft BASIC shape tables. The figures may be displayed by a user program with variable size and orientation under program control. A validating experiment of the mental rotation type is also reported. The figures in that experiment produced results typical of other types of stimuli. In addition, overall reaction time, mental rotation speed, and practice effects were sensitive to the complexity variable.