This quantitative study of imagery in 96 undergraduates addresses the problem of individual differences in the characteristics of mental imagery workspaces. A 20-item questionnaire embodying nine characteristics of mental imagery workspaces was administered to 78 females and 18 males. Analysis of variance by gender disclosed significant higher frequency of mental imagery workspaces reported by males than by females. Characteristics of imagery reported by subjects include presence or absence of mental imagery, color, black and white, movement, images of numerals, ability to control the onset and erasure of the mental imagery workspace and use of imagery to do mathematics. The main finding is that there are statistically significant differences among individuals in the characteristics of their mental imagery. This finding may be important in guiding psychotherapists to determine the capabilities and limitations of the client's imagery workspace prior to using mental imagery as a therapeutic technique. Over 10 percent of the subjects reported using mental imagery of tables or charts that had appeared in their math texts to do mathematical operations, suggesting the importance of including such visual aids in math texts, workbooks and classrooms. (Author/BS)