Over four and a half years, the project will convert five million records from forty-five different source files, cataloged over the past century and a half under a wide variety of rules. Revisiting the original project proposals, I confirmed that we did not justify the expense of authority control at all. It was a given, something so basic to a successful library catalog as to make justification unnecessary. The lack of consistency which would result from merging the historical catalogs of forty-five autonomous libraries conflicted with our understanding of what makes a catalog valuable. Much recent research and development in information retrieval has focused on improving recall, but very little has addressed increasing precision.
Authority control serves both.
Provision of consistent headings, together with a reference structure, allows searchers to isolate the particular author they are interested in and ensures that they find all the available works by that author. Setting the Stage In 1991, when we began to plan for retrospective conversion, authority control at Harvard University was a purely manual affair. There was a convenient fiction that all cataloging records were added to the local system by cataloging staff, and that each heading was therefore established or validated as each bibliographic record was created or claimed. However, the world was more complicated than it appeared. Large batches of records were being loaded from outside sources, often bypassing the cataloging department entirely.