Measuring imaging ability: psychometric testing of the imaging ability questionnaire.

Imaging ability, defined as the ability to create vivid mental images and to experience those images as if they were almost real, has been suggested as a moderator in effective use of guided imagery for symptom relief. Persons with good imaging ability are thought to be more likely to succeed in relieving a symptom with guided imagery than persons with poor imaging ability. The purpose of this paper is to describe the development of an instrument designed to measure imaging ability, the Imaging Ability Questionnaire (IAQ). A descriptive correlational design was used to conduct item analyses and explore psychometric properties of the IAQ. A total of 200 persons from the Midwest completed a 54-item version of the IAQ. Twenty-two items that failed to discriminate among levels of imaging ability were eliminated from the questionnaire. The final version of the IAQ contained 32 items and demonstrated good internal consistency (alpha =.93) and test-retest reliability (r =.92). Support for construct validity of the questionnaire was provided by demonstrating expected differences in IAQ score between persons for whom imagery worked and persons for whom imagery did not work. Future testing and use of the questionnaire in research and practice are discussed.