1. CADIAL search engine at INEX
Jure Mijić1, Marie-Francine Moens2, Bojana Dalbelo Bašić1
1Faculty of Electrical Engineering and Computing
2Department of Computer Science, Katholieke Universiteit Leuven
INEX Schloss Dagstuhl Conference Center, Wadern, Germany
ITI2008 Cavtat

2. Presentation overview
What is CADIAL project?
System overview
Ranking model
Ad hoc results
Conclusion
Future work
INEX 2008 Dagstuhl

3. What is CADIAL project?
Bilateral project between the Government of Flanders and the Ministry of Science, Education and Sports of the Republic of Croatia
Aims of the CADIAL project:
Provide access to a collection of Croatian legislative documents
Enable the use of the Eurovoc thesaurus, an EU standard thesaurus for document indexing and retrieval
INEX 2008 Dagstuhl

4. System overview Built with expandability in mind
Supports multiple information retrieval models
Supports morphological normalization modules
An indexer tool is used for document indexing
Input documents are in XML format
Output is an index database (a base structure for every search engine model)‏
Index database is upgraded with additional data required by the model (various statistical information)‏
INEX 2008 Dagstuhl

5. Ranking model Language model Additional features
Element priors based on element location and depth
Smoothing on document and collection level
Additional features
Support for CAS queries
Support for +/- keyword operators
Simple overlapping element removal
Stemming
INEX 2008 Dagstuhl

6. Ad hoc results Our runs: Three CO runs
One returning only documents
Two returning elements
Three CAS runs with various smoothing factors
No.
Run
iP[0.00]
iP[0.01]
iP[0.05]
iP[0.10]
MAiP 1
co-document-lc6
0.6389
0.5949
0.5051
0.4699
0.2551 2
cas-element-ld5-lc4
0.6684
0.5530
0.4048
0.3248
0.1440 3
co-element-ld2-lc5
0.6907
0.5417
0.4007
0.2920
0.0994 4
co-element-ld2-lc1
0.6718
0.5241
0.3922
0.2963
0.0929 5
cas-element-ld2-lc5
0.6494
0.5203
0.3569
0.2593
0.1134 6
cas-element-ld1-lc6
0.6642
0.5063
0.3652
0.2610
0.1133
INEX 2008 Dagstuhl

7. Ad hoc results
INEX 2008 Dagstuhl

8. Conclusion
Retrieving whole documents performed better than element retrieval at higher levels of recall
CAS queries performed slightly better that CO queries
Higher smoothing at the document level contributed to better performance
INEX 2008 Dagstuhl

9. Future work Other smoothing techniques Pseudo relevance feedback
Incorporating link evidence
Information extraction methods
INEX 2008 Dagstuhl

10. The End
Thank you
INEX 2008 Dagstuhl

11. Language model
INEX 2008 Dagstuhl