The intent of this project is to generate data sets for the research & practitioner community. Data sets should consist of multiple test impressions from the same pair of shoes worn by one person over fixed intervals of time. Ideally the data set would consist of multiple types of shoes (athletic, casual, dress) worn by the same person. For example, collect at least five test impressions from a brand new athletic shoe and every week thereafter for a certain period of time in an effort to document the development of randomly acquired characteristics. Researchers also may want to examine wear patterns over time. It is highly recommended to consult a qualified footwear examiner to confirm randomly acquired characteristics.