Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

SUO: Ontology case study




Folks,
   Bill Andersen and I were speaking a moment ago and he pointed out that I 
hadn't related an application of ontology that we did a while ago.  My hope 
is that this case should point out one simple, concrete application of an 
ontology, in a deployed business environment.
   During the dot-com boom we worked with a Internet-based real-estate 
company to solve a database integration task.  I was surprised to find out 
as we started the project that what consumers know as the Multiple Listing 
Service database that realtors use is actually a collection of some 30,000 
locally-developed databases that record information about homes for sale in 
a particular geographic area.  All the databases cover the same basic 
information, but all the table names, field names, and symbols may be 
different from one database to the next.
   We created an ontology of real estate in first order logic, using an 
upper ontology.  We then "compiled" the ontology by hand into a relational 
database.  We then wrote scripts, again by hand, to map the contents of 
each MLS database into our common database.  The ontology was robust and 
comprehensive enough such that after the first couple databases, and we 
eventually mapped several dozen of them, there were no changes to the ontology.
   The company's web site went live for several months, using our 
ontology-based database, and then they exhausted their funding and went out 
of business.
   Of course this is just an anecdote.  I doubt it's going to change 
anyone's mind who already has a strong opinion about the usefulness of a 
single ontology for supporting integration.  But at the very least, it's a 
concrete instance of the productive use of a particular ontology on one 
commercial integration task.  I've provided references in previous messages 
to other government research projects where we've used ontologies for 
integration as well.
   One impact of an ontology that I find undeniable is that at the very 
least, a formal ontology can serve as a more precise set of comments about 
the meaning of database tables and fields than informal English.
   This also points out some fruitful areas of research for tool 
builders.  It would be nice to compile the ontology to an SQL DB schema.  I 
believe Bill's company is working on that.  Another extremely valuable tool 
would be one that aids in doing the mapping from disparate databases to a 
common database.  I'm doubtful about the prospects for doing that 
completely automatically, but hopefully that tools could be developed that 
would help.
   I hope this is helpful.

Adam



Adam Pease
Teknowledge
(650) 424-0500 x571