Human body motion is represented by a skeletal model derived from image data of a user. Skeletal model data may be used to perform motion recognition and/or similarity analysis of body motion. An example method of motion recognition includes receiving skeletal motion data representative of a user data motion feature from a capture device relating to a position of a user within a scene. A cross-correlation of the received skeletal motion data relative to a plurality of prototype motion features from a prototype motion feature database is determined. Likelihoods that the skeletal motion data corresponds to each of the plurality of prototype motion features are ranked. The likelihoods are determined using the cross-correlation. A classifying operation is performed on a subset of the plurality of prototype motion features. The subset of the plurality of prototype motion features is chosen because its members have the relatively highest likelihoods of corresponding to the skeletal motion data.