Evaluating the readability of instructional visuals

Text readability has developed from a crude means to classify subjective judgment on text characteristics, to a more theoretical position which compares these attributes with learner characteristics. Visual readability may be following a similar evolutionary path to that of text readability. The Picture Readability Index (PRI) developed in this study utilizes an interdisciplinary battery of methods adapted from the fields of linguistics, reading, and cognitive psychology. The PRI is designed to assess the readability of instructional illustrations. Readability refers to the success of the image as defined by its objective or caption. Images can be readable in the sense that they inspire cognitive and affective processing. Photographs with low readability inspire reactions that do not go beyond initial first glance responses.