Region-display spatializations represent documents metaphorically as points within regions. Semantic interrelatedness is expressed by some combination of interpoint distance and region membership. In two experiments, the authors investigate judgments of document similarity as a function of these variables. Distance matters, but region membership largely determines judged similarity; hue further modifies it. Spatial metaphors are a popular approach to visualizing information in such forms as information worlds, information spaces, and cyberspaces.