The complexity of the subject area requires the consideration of such aspects as the location, extraction and evaluation of the data contained in various data bases; the overlap of data between data bases; the changing terminology within the subject field; evolving data base structures; the cost; and the urgency of requests.
Connaissance des faits nouveaux survenus dans le domaine en question ainsi que de la terminologie utilisée pour caractériser les dernières notions des principales disciplines et des disciplines connexes.