The Meaning of "Is"

That’s an easy one, with all due respect to our former president.  As far as the NIF is concerned, “IS” is the inferior salivatory nucleus.  How do we know?

Perform a search in NIF and you will see various terms highlighted in the search results (the current highlighting color is brick red, but we are open to suggestions).   Hover over each of these highlighted terms and NIF will tell you what the term means to the NIF system.  If you hover over “IS,” NIF tells you it’s an anatomical structure. If you right click on it and ask to see “IS” in the Neurolex, it will tell you that IS is an abbreviation for the inferior salivitory nucleus.  This new feature is an example of what is often called “entity recognition.”

In the formal world of knowledge representation, an entity is that which is perceived, known, or inferred to have its own distinct existence.  For NIF, entities are those things like organisms, cells, molecules, and techniques that define our domain.  These entities are represented in the NIF ontologies.  Each entity has its own numerical identifier, sort of like a social security number, that uniquely identifies the entity.  This identifier is used to point to different ways of saying the same things to the same entity.  For example, NIF doesn't care whether you call entity birnlex_2645, the IS, inferior salivary nucleus, or Freddy, for that matter.  They are all (and always) the same thing.

Unfortunately, the richness and complexity of our language makes recognizing entities a tricky thing, as everyone who uses a search engine knows.  Not only can we call the same entity many things, but we can call many entities the same thing.  Chances are that the IS highlighted by NIF in the search results actually is not the inferior salivatory nucleus but the third person form of the verb “to be,” or perhaps it is the initial segment of an axon or the Institute for Science.    Right now, NIF doesn't really know.

In future releases of NIF, we will be working towards improving the accuracy of our entity recognition.  Why?  Because once we know that IS is a brain nucleus, we can find anything that is known about it:  its projections, its genes, the diseases in which it is affected.  A preview of what is coming can be seen in the NIF Cards.

[caption id="attachment_254" align="alignleft" width="300"] Search for IS with NIF Card[/caption]

NIF cards for each entity can be viewed by right clicking over the highlighted term and selecting “Show NIF card” from the menu. NIF cards currently are only implemented for anatomical structures and cells.

For now, however, we hope you will explore the new NIF and develop an appreciation for the difficulties of semantic search by seeing what NIF thinks the results mean.  You may be surprised!