Distribution of citations in databases in a multidisciplinary field

Word‐oriented databases of potential relevance to the multidisciplinary field of emergency management were identified by the University of Illinois, Information Retrieval Research Laboratory under contract to the United States Federal Emergency Management Agency (FEMA). This article is an extension and outgrowth of that contract. It analyzes forty databases for relevance to emergency management by searching each database using an emergency management subject profile, printing a random sample of citations to determine percent of false drops, and ranking the databases according to number of relevant citations. Bradford's law of scatter is shown to apply to this multidisciplinary field, using databases instead of journals and citations instead of articles. No one database provides more than 19% of the literature, however, illustrating that the literature in the field is widely scattered throughout databases. These findings can help in the choice of the specific databases containing emergency management citations and in the determination of how many databases need to be searched in order to retrieve a given percentage of the literature. A companion article in this issue of Online Review — ‘Evaluation of database coverage: a comparison of two methodologies,’ explains the subject profile evaluation method employed in this project and compares it to another coverage evaluation technique.