Conspicuity index – looking for a possible objective measurement of visibility taking context into account.

Paper in proceeding, 2008

An emergency exit sign can be more or less visible. Something has to do with the sign itself: with bright colors it might be more visible than with faint colors. But also the context plays a role: alone on a white wall it will most likely become more visible than on a wall full of brightly colored posters. There is also a subjective side to the matter; you will more likely see the sign in an emergency situation than in an everyday situation. In the field of Information Design there is a need for an objective and easily administered measurement of conspicuity. Today a time measurement using visual search is possible, but often difficult and unpractical to use in real life. In a small pilot study I have tested a new method of conspicuity index, a measurement method where the subject starts by looking at the target whose conspicuity is to be measured, then gradually looks away while attending to the target in the corner of his or her eyes until detection no longer is possible. The angle where detection ends is the conspicuity angle. Previous studies show a high correlation between the conspicuity index and traditional search time measurements. Results from this study show good accordance with intuitive impression of saliency.