Initial exploration of the ASRS database

We applied a standard classification algorithm to a subset of NASA/FAA Aviation Safety Reporting System (ASRS) database. The subset concerned incidents of aircraft altitude deviations. We are exploring the database to address questions such as: Are there 'natural' classes into which the data will fall? How would these classes correspond to recognizable events or situations? Beyond addressing these we want the data to determine directions for further study. We conducted experiments on different data subsections and analyzed diagnostics such as 'message length reduction'; these characterize the classification in terms of its significance and information content. The classification effort was successful in revealing relationships in the data that were in consonance with other studies of the data and expert opinion.