Understanding Perceived Image Quality: New Applications for Verbal Protocol Methodology

Abstract

The present study investigated the effectiveness of ‘cued retrospective verbalization’ used in combination with eye-movement recordings as memory aids to study image quality evaluation of display products. That is, recordings of eye movements during image quality judgments were played back as cues for recalling and verbalizing thoughts which occurred during prior image evaluation. The study also examined the consistency of subjects' image quality evaluation responses over time and whether retrospective verbalization influenced and altered subsequent preference. The experiment consisted of two sessions separated by a 60-hour interval. Subjects in the experimental condition performed retrospective verbalization in both sessions whereas subjects in the control condition did so only in the second session. Judgments of perceptual quality were stable over time, and there was no indication that cued retrospective verbalization influenced subsequent perceptual evaluation. Moreover, subjects in the experimental condition stated the same critical image characteristics for the reasons of their preferences if they had not changed their choices between the two sessions. When there were changes in preference over time, their verbalization protocol indicated clear shifts of attention from one critical image characteristic to another. Cued retrospective verbalization appears to be an effective tool to examine the processes of display image quality.

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