The diffIculties encountered in controlling headings on current cataloging and the special problems in dealing with retrospective records raise the question of just how good a library's authority control can or should be. The only way to guarantee unique, uniform, and correct headings is to examine each record-if not each item-individually. This is at least feasible for original cataloging, but copy cataloging efficiency would be impaired if headings on existing bibliographic records were evaluated routinely. For new cataloging, the bibliographic item is at least readily available for inspection. Physical inspection of the item is clearly impractical
when dealing with converted records for all but the smallest collections. Consequently, even libraries with high authority control standards for current cataloging may need to adopt more relaxed standards for retrospective records. Before commencing a retrospective conversion project, a library therefore first needs to derme its quality standards for authority control and then to determine the degree to which the converted records should approach these standards. Decisions on these points will necessarily inform subsequent choices regarding the means of bringing the retrospective records under authority control.