Turning pictures into numbers: extracting and generating information from complex visualizations

We present a study of complex visualization usage by expert meteorological forecasters. We performed a protocol analysis and examined the types of vis ualizations they examined. We present evidence for how experts are able to make use of complex visualizations. Our findings suggest that users of comp lex visualizations create qualitative mental models from which they can the n generate quantitative information. In order to build their qualitative me ntal models, forecasters integrated information across multiple visualizati ons and extracted primarily qualitative information from visualizations in a goal-directed manner. We discuss both theoretical and practical implicati ons of this study. (C) 2000 Academic Press.