Proposes the establishment of a uniform definition of school dropout which would help to more accurately measure the extent of the dropout problem. The report describes elements of dropout measures and examines factors that account for variation in measures from city to city and state to state. [This document is a reissue of the October 1987 CPRE Research Report RR-003 under the same title (ED298184). Information on original record varies. The original content in ERIC contains additional pages that provide sponsor and audience information.]