UKOLN MODELS 3: Workshop report

10-11 July 1996, Stakis Hotel, Bath
Organised by UKOLN with eLib support. Chaired by Richard Heseltine

Report by Lorcan Dempsey and Rosemary Russell

Summary and recommendations


This was the third MODELS workshop. Its scope was described as follows:

Library catalogues represent an important resource discovery tool for printed scholarly material. However, a user who wishes to discover the existence or location of a particular item may have to individually visit, in an unguided way, a variety of catalogues. There are also significant bibliographic resources which may not be available for him or her to use. Catalogues include individual library catalogues, union catalogues and significant national services.

The aim of this workshop is to move towards a shared view of the technical requirements for unified national resource discovery systems in this area, acknowledging the organisational and business environments in which services now operate or are being developed. It will identify technical and organisational impediments to national resource discovery services and discuss ways in which they might be overcome. The primary focus will be on the higher education environment, with due reference to other sectors.

The focus of the workshop is on discovery. Other issues, such as requesting, are being dealt with in other parts of the MODELS project.


There was general agreement that the current bibliographic resource was fragmented and poorly articulated and that services built on some more organised combination of existing resources were desirable. At this stage of development, it was recognised that a national union catalogue was infeasible for technical, organisational and service reasons. A distributed approach which provided unified access to existing catalogues was desirable, although a fully distributed option providing parallel access to all catalogues was undesirable for reasons of scale.

To clarify discussion, the notion of 'clump' was introduced. A clump is an aggregation of catalogues. A clump may be 'physical' where it has a continuous physically aggregated existence. Example of physical clumps are COPAC (the CURL OPAC), the BL OPAC (made up of BL catalogues), the SLS and BLCMP union catalogues, and Viscount. A clump may also be 'virtual', where the records from the participating catalogues are not physically brought together. How closely coupled the members of a virtual clump might be was seen as a discretionary matter, depending on the particular service scenario involved. The relationship might be entirely dynamic or user-defined, or it might be determined by long-standing service agreements among a group of service providers.

In breakout sessions and subsequent discussion some desiderata for an organised approach were outlined. These cluster into User issues and Catalogue issues and are presented below.

User issues
Ease of access; Consistency; Reliability; Availability; Quality; Relevance; Free at the point of use (?); Authoritative; Choice; Completeness.
Catalogue issues
Predictable behaviour (consistency in indexing, etc.); Include collection-level descriptions; Capable of being aggregated in helpful ways; Terms of availability for discovered material; Sustainable; Service standards.

There was a recognition that a controlled environment was necessary if desiderata were to be addressed.


What standards would be necessary to allow the construction of distributed national resource discovery systems? Areas where standards were identified are listed below.

User interface (Z39.50/Java/windows, WWW); Referral services (WHOIS++, LDAP, ?); Search and retrieve (Z39.50); Collection level descriptions (?); Service levels (?); Authentication (?)

User interface and general architecture
Diagram showing architecture

A three-tier architecture was presented. A 'thin client' (typically a web browser or windows interface) was likely to be the preferred user instrument. A 'broker' service gives access to various services. The broker might be more or less rich. Minimally, for example, it might offer Z39.50 client functionality. It might open multiple Z39.50 sessions and consolidate the results. It might offer other services (request, etc). The future importance of object technologies, Java in particular, was noted as a way of delivering applications to the desktop.

It was anticipated that 'broker' services would be provided at various points in a service chain and would provide different levels of service. The broker might be a desktop application, a local campus service, put in place by an information provider or some third party.

Collection descriptions
There was an assumption that users would sometimes need to have collection-level descriptions, however they are provided. This was for a number of reasons. In general it aims to reduce search parallelism and redundancy. On some occasions a user would wish to do a higher level search to identify catalogues of potential interest. In some cases, a catalogue might not contain item level descriptions for some collections (e.g. a slide collection); a collection-level description might be better than no other representation. Collection level description might form the basis for defining 'virtual clumps', or allow users to navigate sensibly through available resources; they could also help determine the likely value of a visit to a library. It should be noted that there is not necessarily a one to one relationship between collections and catalogues. All the items in a collection may not be represented in a catalogue. A catalogue may describe more than one collection. Less typically, more than one catalogue may describe one collection.

Several approaches to collection description were mentioned, including ISO 2146, Conspectus, and the Z39.50 profile for access to digital collection. A complementary approach was also briefly discussed, involving the generation of 'centroids', inverted index style representations of database content, which could be shared and searched in various ways.

Search and retrieve
There was general agreement that there was no alternative to Z39.50 here. To meet the stated desiderata, however, implementors would have to additionally agree on particular options (e.g. mappings between attribute set elements and local indexes) to ensure predictability of service and consistency of results. Other implementation issues would also require attention (e.g. communicating availability data, non-delivery of MARC records to avoid record re-use, and so on).

'Virtual clumps' could be created by searching several resources and consolidating the results.

Referral services
Collection-level descriptions need to be made available for searching in some way. Again, a variety of approaches are possible. They could be served up through a directory service (WHOIS++, LDAP, ...); they could be made available through the Z39.50 explain service; they could be collected in a central database; and so on.

Service levels
It would be useful if libraries had consistent ways of describing these. As a minimum, whether and under what conditions items are available for loan need to be noted.

The subject of another eLib/ACN initiative. A national framework should be supported. However, this may take two years or more to build. Interim measures will be needed.


To be effective, it was important that developments proceeded within a well-understood and ordered framework which imposed no unnecessary overhead.

To participate in a 'national discovery system' it was decided that individual catalogues should meet some minimum criteria. These should be formally described in a Catalogue Profile, and providers would register the Profile with a National Agency. Initial components of such a profile, as developed at the workshop were:

A national agency would perform several functions:

It was recognised that such an agency might have a broader remit in relation to other collections of scholarly materials (archives, electronic texts, museum objects, etc) and that it should be inclusive so long as this did not dissipate its focus. The Agency should have a truly national role and not be a creature of Higher Education alone.


Medium term (6-9 mths)

Intermediate (3 months)

September 1996