This study investigated determinants of the internal structure of categories of directed behaviours. For the categories Sport, Gardening, Craft, Making music, and Housekeeping, proximity to the category's central tendency and usefulness in accomplishing category-specific goals were compared as predictors of prototypicality ratings. In a preliminary study, subjects suggested activities and goals for the five categories. In the main study, subjects estimated the prototypicality of these activities for the categories, their usefulness in attaining the category-specific goals, and the similarity of the activities among each other. Family resemblance scores were derived from the latter ratings. It was found that family resemblance and usefulness in attaining category-specific goals were about equally useful in predicting the actual prototypicality ratings.