Ontology Alignment Excercises

In this project you will use and learn about the Alignment API that is used in the evaluations of the yearly Ontology Alignment Evaluation Initiative (OAEI). Have a look at the OAEI's home page at http://oaei.ontologymatching.org/. We will use the Alignment API of the 2008 OAEI. This is available under 'Processing tools' at http://oaei.ontologymatching.org/2008/.

Read about the Alignment format and API at http://oaei.ontologymatching.org/2008/align.html (A description is also available at http://gforge.inria.fr/docman/view.php/117/251/align.pdf. Some other information is available at http://alignapi.gforge.inria.fr/.)

The project is divided into 4 tasks. In task 1 you will learn how to use the Alignment API. In task 2 you will run matchers on a data set and discuss the results. In task 3 you can write your own matcher. In task 4 you will reflect on what alignment strategies would work well for what kind of ontologies.

Task 1

Go through the tutorial for Alignment API provided by Jerome Euzenat at http://alignapi.gforge.inria.fr/tutorial.

OBS: some techical changes to the tutorial for Windows users at the end of this page.

This tutorial will show you how to use and run the Alignment API. You will learn to use matchers, filter using single threshold and evaluate the quality of the suggestions of the alignment methods. Run all examples. Try to answer all questions and check your answers with the discussions under 'show discussion'.

Task 2

Use the benchmark2008 test library at http://oaei.ontologymatching.org/2008/. Run (some of the available) algorithms already implemented in the Alignment API package on the benchmark2008 test library and evaluate their performance. Are the results as you expected? Try to explain the results.

Task 3

Implement your own matcher. (Write subclass of existing Alignment class). Run on the benchmark2008 test library and evaluate its performance. Are the results as you expected? Try to explain the results.

Task 4

Study the other test cases in the OAEI 2008. What kind of matchers would be suitable for these cases? (Observe that no expected solutions are given for these test cases. This means that you could run your matchers on the test cases, but you cannot evaluate them.)

Changes for windows users

align-3.5 (http://gforge.inria.fr/frs/?group_id=117) works best with the tests in "Embedding" section.

1) setenv CWD `pwd`
changes:
set CWD=[the absolute directory path of 'tutorial']
for example:
set CWD=Z:/AlignAPI/AlignAPI/html/tutorial

2) All commands involving "Java" and "Javac"
changes:
replace "file://$CWD/" with "file:///%CWD%/"
for example:
$ java -jar ../../lib/procalign.jar file://$CWD/myOnto.owl file://$CWD/edu.mit.visus.bibtex.owl
should be
$ java -jar ../../lib/procalign.jar file:///%CWD%/myOnto.owl file:///%CWD%/edu.mit.visus.bibtex.owl

3) All commands involving "Javac"
changes:
replace the delimiter ":" between different classpaths with ";"
for example:
javac -classpath ../../lib/api.jar:../../lib/rdfparser.jar:../../lib/align.jar:../../lib/procalign.jar -d results Skeleton.java should be
javac -classpath ../../lib/api.jar;../../lib/rdfparser.jar;../../lib/align.jar;../../lib/procalign.jar -d results Skeleton.java