Great Britain Historical Geographical Information System (GBHGIS)

Data standards

The GIS sector as a whole has tended to develop around proprietary "standards" associated with particular companies. The new Great Britain Historical GIS project has rejected this approach and has implemented a series of open standards:

Open Geospatial Consortium

The OGC was until recently the "Open GIS Consortium". It has published a series of linked standards, including Geographical Mark-Up Language and Web Map Server.

Alexandria Digital Library Gazetteer Development

The ADL gazetteer activity, led by Linda Hill, has developed a gazetteer content standard and feature type thesaurus, which are supported by the GBH GIS, and a service protocol which we aim to support. The service protocol would enable a network of gazetteer servers, maybe covering different parts of the world, to cooperate in answering a single query from a web user. Much of the technical discussion about the new GBH system has taken place on the associated Geographic Referencing mailing list.

Data Documentation Initiative

One of the central problems faced by the GBH project in designing its new system was how to hold millions of statistical datavalues in just one table, instead of hundreds. Our solution is a relational implementation of the Data Documentation Initiative's Aggregate/Tabular Data Extension. The DDI Alliance is an international consortium of data libraries.

Dublin Core Metadata Initiative

The Dublin Core is a "lowest common denominator" for on-line cataloguing system. Many funding bodies require that digitisation projects support it, although that does not get a GIS-based project all that far.

Language Codes

Although much, maybe most, historical information is also geographical information, this means that it contains placenames, not coordinates. One limitation of conventional GIS systems is that they do not give the historian much help in tracking placenames, and how the name of a particular location changes over time. That partly means recording the languages names are in, and this needs to be done using standard language identifiers. The best known system is the ISO 639-2 standard, but this provides poor coverage of "dead" languages. The GBH project uses two complementary sets of codes: Ethnologue for modern laguages, and Linguist for historical ones.