spobooks5621225.0001.001 in

    The BT Library offers 800 online journals to its user community, within the limits of the publishers' agreements. The collection of online journals is supplemented by a disintermediated document delivery service providing what might be called near-online journals. Articles not available online on the Library's server can be requested in a straightforward way and are usually delivered in two to three days.

    A noticeable impact of the move from the physical to the digital library is in the distribution of the user base. In 1994 the library served the research community almost solely. In spite of current awareness bulletins, which were distributed throughout the company, and a document delivery service to supplement this, approximately 90% of the library's usage was from the Adastral Park site. By the end of 1998, when ACM, IEE, and IEEE journals became available on the server in addition to the in-house journals and a selection of titles from Elsevier, this figure had gone down to 61%. In 1999 the Library's collection was enhanced with the addition of material from ABI/Inform. Since then, the balance has shifted so that only 40% of users come from the BT's Adastral Park site.

    As part of this study, the usage of the 3,500 potential users at Adastral Park was examined. These users are readily traceable, because they use relatively static IP addressing, allowing a more detailed study of individual usage.

    In 1999, 1,091 users from BT ACE read 9,108 journal articles from the digital library 12,919 times. (These figures exclude journals from the ACM Digital Library and from the selection of other journals available only on the publishers' sites, where usage data is not available.) In comparison, the library had 1,500 users registered for access to the physical library and lent fewer than 8,000 documents in the same period.