Since imagery is a unidimensional variable, all measures of imagery, both questionnaires and behavioral, should be correlated; this, however, has not been supported by earlier research. Therefore, a new questionnaire on mental imagery--the Differential Imagery Questionnaire (DIQ)--was developed which taps four types of imagery: word imagery (WI); picture memory (PM); imagery manipulation (IM); and fantasy (F). The questionnaire was then validated against four behavioral measures of imagery. With one exception (WI), the questionnaire subsections significantly correlated with the respective behavioral measures. This finding suggests that self-reports of imagery clarity (questionnaires) may indeed be used to predict other specific behaviors. At this point, there remains a need for further development of the DIQ. Although statistically significant relationships were found between the factors and the behavioral tasks, the relationship was relatively low in terms of percent of common variance. (A copy of the DIQ is included.) (Author/RD)