Model and representation: the effect of visual feedback on human performance in a color picker interface

Reviewer: Raphael M. Malyankar

Douglas and Kirkpatrick describe studies on human performance in color matching, using the results to hypothesize about relationships between users' mental models and the visual representations modeled. The authors attempt, first, to distinguish the effects on user performance of using different color models (in the studies reported, red, green, blue, or RGB, and hue, saturation, value, or HSV) from the effects of provision of different levels of feedback by the color selection interface. The results report no significant performance differences between the RGB and HSV color models. Feedback level was discovered to affect accuracy but not time taken to match. A second study is also reported, consisting of qualitative analysis of user actions during the matching process, which captures subjects' navigation in the color space and thus their strategies for search in the color space. The analyses suggest that hill-climbing strategies are used for this problem (at least, with the interface used in the experiment). The implications for color picking and suitability of color models for human problem solving on this kind of problem are discussed, as are possible effects of biasing of results due to the nature of the target colors and interface capability, and implications for current widely used color selection interfaces. The authors believe that visual feedback and interface design are more important than the color model used. Their discoveries about the non-significance of color models on color picking (or at least, of the HSV and RGB models) are interesting and, though not entirely unintuitive, may be useful for interface designers who need to add color-picking-like facilities. Follow-up experiments on the relationships between human search behavior, feedback types and levels, and the structure of search spaces should be interesting.