1. Associative and Spatial Relationships in Thesaurus-based Retrieval Harith Alani 1, Christopher Jones 2, Douglas Tudhope 1 1 School of Computing, University of Glamorgan {halani,dstudhope}@glam.ac.uk 2 Department of Computer Science, University of Cardiff c.b.jones@cs.cf.ac.uk

2. OASIS - Ontologically Augmented Spatial Information System Aims: –Investigate terminology systems for thematic and spatial access in digital library applications and in particular: Investigate retrieval potential of geographical metadata schema consisting of rich place name data, with limited locational information Explore retrieval potential of reasoning over underlying semantic relationships

3. Presentation Overview of OASIS Spatial query expansion Semantic distance measures for query expansion. Role of thesaurus associative relationships. Conclusions

4. OASIS datasets Art & Architecture Thesauri (AAT): thematic descriptors - town, arrow, axe, etc. (J. Paul Getty Trust) Thesaurus of Geographic Names (TGN): place names, hierarchies and centroid co-ordinates. (J. Paul Getty Trust) Bartholomew digital map data: place names, co-ordinates, and adjacency relationships Ontological schema implemented using Semantic Index System (SIS), also used to store the data collection Royal Commission on the Ancient and Historical Monuments of Scotland (RCAHMS): dataset of Scottish archaeological sites and objects

5. OASIS Schema TGN TGN & Bartholomew RCAHMS AAT

6. Indexing Artefact DE 121

7. OASIS UI - Selecting Items

8. Spatial Expansion

9. Semantic distance BT RT edged weapons weapons Axes (weapons) Battle-axes throwing axes franciscas tomahawks (weapons) Axes (tools) staff weapons gisarmes halberds pollaxes harpoons hatchets <wood-cutting and finishing tools> Pulaskis Tools & Equipment Weapons & Ammunition AAT Hierarchies

10. RT Expansion Experiments Sometimes RTs are used in a very loose way This causes problem for term expansion over RTs We developed a set of experimental scenarios for more precise control in RT expansion

11. BT/NT Expansion only

12. RT Expansion included

13. Inter-Hierarchical RTs not Traversed

14. Specialisation of RTs Alternative approach is to make use of a richer set of thesaurus relationships by specialising the main relationships Allows optional filtering on RT subtypes In creating the AAT, a subset of RT types was employed by thesaurus editors

15. AAT RT Codes & Rules 1. Alternate hierarchical relationship –Alternative broader/narrower terms (arrows - edged weapons) 2. Whole/Part relationships (arrows - nocks) 3. Interfacet links (19 subtypes). –Activity - Equipment Needed or Produced (arrows - archery) 4. Distinguished-from links (axes (weapons) - axes (tools) ) 5. Conjuncted-term links (arrows - bows (weapons) )

16. Semantic distance edged weapons weapons Axes (weapons) Battle-axes throwing axes franciscas tomahawks (weapons) Axes (tools) staff weapons gisarmes halberds pollaxes harpoons hatchets <wood-cutting and finishing tools> Pulaskis Tools & Equipment Weapons & Ammunition AAT Hierarchies BT RT (1) RT (4)

17. Specialised RTs

18. Conclusions We have explored the use of semantic distance measures for spatial and associative (RT) thesaurus relationships:- –distance measures can be used with place name hierarchies, as used in online gazetteers and geographical thesauri, when footprint data is limited The experimental RT scenarios suggest a potential for specialisation of RTs into different sub-types, and optionally linking RT type to query context Relationship subclasses used in thesaurus design should be retained for later use in retrieval