Robustness of the Photo Anxiety Questionnaire: changing the sequence of stimuli and photographs.

In a split-ballot experiment (N=458) we tested, first, to what extent the logical presentation of the Photo Anxiety Questionnaire forces respondents into the usual response pattern, that is, a higher reported anxiety on items mentioning a time closer to dental treatment. Secondly, we tested whether subjects use the nonverbal response scale or merely use the position of the photographs on the scale when answering the questions. The original questionnaire had the highest reliability and was least influenced by response bias. Changing the order of the photographs on the response scale did not alter the response pattern, implying that subjects do react to the intensity displayed in the photographs and not just to the position of the photograph on the scale. Because changing the order of the items altered the response pattern only marginally, the response pattern usually found does not seem to be the direct consequence of the logical presentation of the Photo Anxiety Questionnaire.