This week, I am at the 201o Semantic Technology conference where there are technologists who have built ontologies.   So this seems like the location to find out  what exactly is the difference between an ontology and a taxonomy and what skills will matter.

In the ontology world, a taxonomy strictly speaking, is a hierarchical arrangement of terms.   Taxonomists populate term nodes and decide what the form of the term is, any variants, equivalents, and semi-equivalents and create hierarchies.   Ontologists do the heavy lifting — they decide what the classes will be and define the links and generate RDF and OWL.

But there is a bright spot in this rather dull picture of  taxonomy work.   The most progressive and insightful taxonomists insist on sorting terms into facets or classes. These facets are derived from an analysis of user needs, content, and domain knowledge.   The core of an ontologists work is   also to define classes or facets and links between classes.   These links between facets can then be inherited or asserted between classes.    A taxonomist who hasn’t thought about classes and design will create a taxonomy that looks like spaghetti, and an ontologist who lacks that skill can create an ontology that makes bad inferences and assertions.

The bottom line is that there is overlap between taxonomy and ontology — so I would like to suggest a term to describe this synergy:  Taxo-ology.    By thinking in terms of Taxo-ology,  we can begin to overlap and have synergy between taxonomists and ontologists:

  • Facets and classes:  Both taxonomists and ontologists need to create classes in which to classify terms.
  • Discipline in Creating Homogenous Hierarchies:  Hierarchies, ideally, should have homogenous properties. For example, Secretary of State is a constitutional office of the United States;  Hillary Rodham Clinton is filling that role, but it is one of many roles she has had.  Christine Connors,  a semantic web guru, uses “Prince of Wales” as her example. That role is there whether or not Charles is Prince.  It is part of the institution of English Monarchy.   Even for the practical reason of longterm maintenance,  these entities need to be in their own class (facet) and linked.
  • Greater Use of Linkages using Associative Relationships: Once terms are sorted homogenous buckets, associative relationships (sometimes with semantic labels for the relationship) can be used to link between classes or  term nodes within a class
  • Better Skill Sets:   Someone who is a Taxo-ologist knows how to use rich ontology tools, like TopBraid, understands OWL and XML output but can also adapt to other tools and content management software such as auto-categorization.  A taxo-ologist can apply the best practices of building classes/facets, homogenous hierarchies, and developing associative relationships
  • Better models for paying Taxo-ologists:  Taxonomists sometimes get paid by the number of terms built-out, but in the world of taxo-ology, compensation needs to be based on results — sometime strategic (is our organization collecting, sharing and exchanging the information  changing market, technical and economic conditions) to tactical need to the right SOP at the right time.  Search, for example, is a great example of how less is more, when good tax0-ologists can make smaller, sleeker taxologies  that can be uses to auto-tag concepts across facets.  Or they create smaller taxonomies that have higher matches to user queries because of use of variants.

Taxologists seems like a good word to help bridge the gap between these disciplines, but there needs to be a discussion and synergy between the taxo community and the ontology world.     Taxonomists to apply more discipline to how they do their work and embrace the autocategorization and semantic tools that make it easier to process content.    The semantic world can save some time  in its development process by learning from the practical experience taxonomists have built by being in the enterprise, libraries, doing card sorts, understanding user experience, analyzing content, and merging all that with domain knowledge.

My goal this week is to find out more about what will help semantic technologies gain more traction, what are the practical, killer applications, and what are the future skills.    Be sure to stop by Christine’s booth to find out more about how ontologists can help with strategic information management and technical integration with semantic web technologies.

~ Marlene Rockmore (blogging from SemTech San Francisco 2010)