A tutorial companion for the Alignment server

This version:
http://alignapi.gforge.inria.fr/tutorial/
Author:
Jérôme Euzenat, INRIA Rhône-Alpes

Here is an illustration of the Alignment API tutorial using the alignment server.

This tutorial has been designed for the Alignment API version 3.0.

Launching the alignment server for the first time

This tutorial can be used by locally launching an Alignment server or by using a publicly available Alignment server. We explain here how to install the alignment server.

Connecting through the server with an HTTP client

Once the server has been installed, it can be accessed using http://localhost:8089/html/. This provides access to two menus. The first one is the user menu:

The second one is the management menu:
You can browse in these menus to see what is available.

The data

The data is the same as that of the genuine tutorial. We will, however, use the versions which are available on the web at http://alignapi.gforge.inria.fr. They can be seen here:

edu.mit.visus.bibtex.owl
is a relatively faithfull transcription of BibTeX as an ontology. It can be seen here in RDF/XML or HTML.
myOnto.owl
is an extension of the previous one that contains a number of supplementary concepts. It can be seen here in RDF/XML or HTML.

Matching

Your firts matching task can be achieved by selecting the "Match ontology" button in the user menu:

As most of the tasks through the Alignment server, it provides a result under that form:
By clicking on the link, one can obtain the HTML display of the obtained alignment:

We will see later how to obtain the same result in different formats.

Other algorithms can be used by selecting other algorithm names or by passing different arguments to the same algorithm. The two algorithms used in the tutorial can be called as follows:

Ticking the "force" checkbox is necessary, otherwise the server will return the existing alignment using the same algorithm (i.e., the one previously computed).

Look at the results: how are they different from before?

We can see that the correspondences now contain confidence factors different than 1.0, they also match strings which are not the same and indeed far more correspondences are available.

We can do the same with the other measure (the smoaDistance):

Manipulating

As can be seen there are some correspondences that do not really make sense. Fortunately, they also have very low confidence values. It is thus interesting to use a threshold for eliminating these values. Let's try a threshold of .33 over the alignment (with the -t switch):

Trimming, as most operations in the server, generate a new alignment:

As expected we have suppressed some of these inaccurate correspondences. But did we also suppressed accurate ones?

This operation has contributed eliminating a number of innacurate correspondences like Journal-Conference or Composite-Conference. However, there remains some unaccurate correspondences like Institution-InCollection and Published-UnPublished!

We can also apply this treatment to other methods available:

More work: There is another switch (-T) in Procalign that specifies the way a threshold is applied (hard|perc|prop|best|span) the default being "hard". The curious reader can apply these and see the difference in results. How they work is explained in the Alignment API documentation.

Other manipulations: It is possible to invert an alignment with the following command:

WE NEED A SCREEN DUMP HERE

Output

From the server, it is possible to generate all the formats available at the command line (depending on your browser, this may require to see the source of returned documents). This is achieved by using the "Retrieve an alignment" button of the user menu:

Here is a result in OWL:

One can ask for the result as SWRL:

Or in XSLT:

Evaluating

This part is not yet available through the server

Embedding

If you want to embed matching solutions in an applications, then you should look at the genuine tutorial.

TODO: Explain embedding of a matching system in the alignment server.

Further exercises

More info: http://alignapi.gforge.inria.fr

Acknowledgements

The format of this tutorial has been shamelessly borrowed from Sean Bechhofer's OWL tutorial.


http://alignapi.gforge.inria.fr/tutorial/server.html


$Id: index.html 384 2007-02-02 11:09:40Z euzenat $