In modem, shared computerized cat aloguing, the interrelationship of types of record usage means that the quality of the source bibliographic records, and any changes made to them after initial creation, can affect users, sometimes in significant and unforeseen ways. Reports on a research project, carried out by the UK Office for Library and Information Networking (UKOLN), Bath University, using bibliographic records on the BLCMP Database, to investigate record quality. The tech nique used to measure the quality of the database was a simple count of the number of records edited. Overall, the standard of records available to member libraries in this large shared cataloguing database was found to meet the needs of the majority of member libraries, with records found for approximately 90 per cent of items, and around 80 per cent of the records found, being used without editing. As more libraries automate, and with the increasing ability for users to search catalogues of institu tions other than their own over net works, the quality of retrospectively converted records needs to be addressed.