National library bibliographic record availability: a long-term survey

The British National Bibliography Machine Readable Cataloguing (BNBMARC) Currency Survey, carried out on the British Library database and using a sample obtained from a variety of public and academic libraries, is now entering its fifteenth year. The results of the survey provide a performance assessment indicator known as the hit rate. The variations in hit rate over the years are noted and possible causes are reviewed. The impact of a number of British Library initiatives (e.g., Currency with Coverage, Cataloguing-in-Publication record purchase, Copyright Libraries Shared Cataloguing Programme) intended to improve the performance of the service are examined. Overall, the results of the survey indicate that the British Library has achieved a fairly high level of performance over the past few years; the sustainability of this level is difficult to predict. Finally, the possible influence of external factors on the performance level in the future is considered.