Presentation on theme: "James Reid Project Manager EDINA. The geoXwalk project funded under JISC IE Development Programme –builds on Phase I scoping study –aims to develop a."— Presentation transcript:
The geoXwalk project funded under JISC IE Development Programme –builds on Phase I scoping study –aims to develop a demonstrator gazetteer service suitable for extension to full service. time-frame: start 1 June 2002 for 1 year project partners: EDINA and UK Data Archive aim: to develop a proof of concept demonstrator
JISC Information Environment -geoXwalk as shared service Portal Content providers End-user Portal Broker/Aggregator Authentication Authorisation Collectn Desc Service Desc Resolver Instn Profile Shared services Portal Provision layer Fusion layer Presentation layer geoXwalk
Geo-referencing: thats whats special about the spatial subject content most often referenced by topic … … but much (80%?) can be referenced to specific geographic places broad disciplinary base for more powerful geographic searching –across the social, life & physical sciences as well as the humanities –also from libraries, archives and museums –now from digital libraries, service providers & data providers geo-referencing thus a way of viewing information content: – subject, people, place and time geographic co-ordinates are persistent regardless of name, political boundary or other changes
Why this is difficult... How to search geographically given that : e.g. a postcode, a placename and an administrative area are all valid geographies and yet every information system cannot know about all the possible variations of what constitutes a geography! Problem compounded by inconsistency of use even in the standards e.g. placenames evolve, have alternative names Long history in UK of boundary changes and changes in the geographies used to record things e.g. electoral ward boundary changes …
There is underlying complexity, such as Multiple Geographies …
Make variations in definitions of geography transparent Provide a means to crosswalk geographies i.e. translate one geography into another - hence the name Geographic agnosticism The vision How? A digital gazetteer that stores the different geographies and can implicitly resolve the relationships between them Provision as a service to service other services
Gazetteer - A list of geographic features together with their associated spatial location Digital Gazetteer - An electronic list of geographic features together with their associated spatial location (An authority database of places (and features?)) Digital Gazetteer Service - A network-addressable middle-ware server supporting geographic referencing and searching. A shared terminology service.
Why not just use hierarchical thesauri? ( part of the Document Tradition) Comment: one type of simple relationship between entries is exploited entries ordered from very general to very specific (BT, NT) can efficiently determine what a given area contains normally structured to handle alternative names (SY) Xrigid structure, one view only, typically geo-political entities can belong in many hierarchies and new relationships evolve Xnames may not be unique Xcannot deal with spatial proximity / contiguity Xno way to relate to other geographies, e.g. postcodes Xlack of simple hierarchies in UK (and other old) geographies … United Kingdom………………………… (nation) England …………………………..(country) Devon………………………….. (county) Barton………………………………..
Uses of geoXwalk Digital Gazetteer Service 1. As shared service, enabling other information services to support full range of spatial searching (query constraints) 1.no need to hold all data (at service) to resolve spatial query 2.uses co-ordinates and (implicit) spatial relationships to cross- walk between geographies 3.machine-to-machine (m2m) interaction to shared service 2. As reference facility for researchers, libraries & museums –including means to resolve variant names etc. 3. As online facility to assist metadata creators and means to semi-automatically geo-reference existing resources
Reference use Information server Searching (1 - use cases) Geo-parsing & indexing The geoXwalk Server geoXwalk Use Cases Searching (2) e.g. Where is Aberdour? On what river is Dundee situated? By what alternative names has York been known? List me all places ending with kirk
Supporting cross searching: geoXwalk in the Common Information Environment Coordinate footprints - Dundee (334995, 729203, 350609, 734710) Places : Barnhill Broughty Ferry Craigie Douglas And Angus Fintry Lochee Monifieth West Ferry <
Supporting service searching: Photographs of towns along the River Tweed Place name - River Tweed Feature Type: River Relation: near Distance: 1/2 km Target type: towns Places... Peebles Innerleithen Melrose Kelso Coldstream Berwick upon Tweed Image finder server (Images indexed on place names)
As online facility to assist metadata creation Most of the extant resources in the JISC IE have some form of spatial reference e.g. placename, county name, postcode A geoparser has been developed which will assist in the semi-automatic indexing of these resources by using the gazetteer as reference. The results of the geoparsing can be used to update the documents metadata, making it directly geographically searchable.
Developments to Date 1.Creation & population of GB gazetteer database with: 1.Enhanced OS 1:50,000 Placename Gazetteer 2.Digital boundary data (UKBORDERS) 3.Additional Place Name Variants (partial for Scotland and Wales) 4.Derived multi-source data e.g. named woodlands and lakes based on hybrid 1:50K gazetteer and OS products 2.Development of spatial extensions to database to support enhanced geographic search capabilities 3.Development of middleware to support m2m and interactive searching 4.Support for and testing of alternative query protocols -ADL / Z39.50(?) 5.Development of a geoparser to support semi-automatic indexing
Ongoing Work and Issues Merging geo-data from different scales & from different sources –how to accommodate historical data –positional accuracy & expression of confidence? –how to minimise effort in de-duplication of place(s)? places have multiple names, types, and footprints need to be able to identify duplicate entries for the same place Presenting geo-names on different occasions? –many variant proper names, what is preferred? what is the name authority body? - none in the Scotland or the UK preferred name varies with location and use and culture –there are language and character code set issues –standard codes for postal addresses and other geographies IPR issues in metadata; and hence terms & conditions of use Service performance issues and appropriate protocols
Contact details James.Reid@ed.ac.uk EDINA, Data Library, University of Edinburgh telephone +44 (0)131 650 3302 For information on geoXwalk project: www.geoXwalk.ac.uk
<gazetteer-service xmlns="http://www.alexandria.ucsb.edu/gazetteer" version="1.1"> standard Query for a placename <gazetteer-service xmlns="http://www.alexandria.ucsb.edu/gazetteer" xmlns:gml="http://www.opengis.net/gml" version="1.1"> -0.02988,51.45753, 1.30798,52.07042 standard Query by feature type and bounding box XML query fragments
Task: Find resource about 'Liverpool docks Search using a traditional gazetteer might yield: … that means more & better hits …. !!! Using spatial proximity in an active gazetteer, the search can be widened: PlaceCounty/UALiverpool BebbingtonWirral BirkenheadWirral BootleSefton New BrightonWirral SeacombeWirral SeaforthWirral WaterlooSefton co-ordinates allow (near) co-located places to be co-identified.
Supporting cross searching different services geoXwalk Server Content Provider CContent Provider A Content Provider B Coordinate footprints Parish names Place names Portal service Post code: L34 0HS? Find resources for this postcode (NB postcode often used to geo-reference survey data files) Knowsley 340900,392300 - 347217, 397660 BX003 <