This chapter attempts to take an initial step in constructing an introspective measure of imagery ability based on present theories and findings on the structure of the imagery system; one that will be of practical use in investigating the role of imagery in cognition. Two factors were considered in the construction of the questionnaire: the items and dimensions rated. Five items were selected that were either the same as or very similar to the type of items used in the five spatial tests with which the questionnaire was to be compared. The presentation of these items was also in a similar style to that of the items on the spatial tests. A variety of ratings was made for each item imagined. These were of two kinds, ratings of the subjective ease of a hypothesized process and ratings of pictorial aspects of an image that could reflect underlying processes either on their own or by interaction with each other