A review of existing practice |
...an eLib supporting study |
The aim of GILS, known both as the Government Information Locator Service and the Global Information Locator Service, is to make it easy for people to find information of all kinds, in all media, in all languages, and over time [GILS]. Information providers can describe anything with GILS including Web pages, books, data-sets, people, events, meetings and other physical objects. For networked information, GILS supports 'hyperlinks' for network access to the resource described and to related resources. GILS uses the Z39.50 search and retrieve protocol to provide access to information (GILS records) held in GILS compliant databases.
GILS has a Z39.50 application profile [GILSPROF] that has been approved by the Open Systems Environment Implementors Workshop/Special Interest Group on Library Applications (OIW/SIG-LA). The service was originally set up by the US Federal Government in order to provide the general public and its own employees with a means for locating useful information generated by the many government agencies. As such its constituency of use is potentially very broad. In theory, many different agencies are likely to use a variety of staff to generate their part of the overall GILS framework. In practice, some agencies are using GILS as generic metadata records for many resources and others are hardly using it at all.
GILS Data Elements are available in an extended attribute-value pair format - some of the elements are constructed from two or more sub- elements. For example, the Controlled Subject Index element is a grouping of sub-elements for Subject Thesaurus and Subject Terms Controlled. The grouping can be nested and is in this case; Subject Terms Controlled itself is a group formed from a repeatable sub-element called Controlled Term. There are approximately 90 GILS elements of which about 40 are considered to be core' elements. The GILS Application Profile also provides a mapping to and from USMARC Tags and GRS-1 record syntax.
GILS records can be used to describe many different kinds of resources including 'collections' of resources, for example Web-sites, data-sets, CD-ROMs, etc. Furthermore, any level of aggregation can be supported in GILS. Typically, specific policies for any particular set of locator records are documented in a collections policy' and/or 'usage guideline'. A 'collections policy' documents the rules for inclusion of candidate locator records within a particular collection.
The Cross Reference elements of the GILS Element Set provide for the ability to describe relationships between records. The Cross Reference element subsets are also intended to be used inside Controlled Subject Index Subject Thesaurus structures to describe where to acquire and reference the thesaurus.
Andy Powell, UKOLN