[seek-kr] RE: Please tear this apart...

[Shawn Bowers]

On Mon, 8 Sep 2003, Rich Williams wrote:

> 
> Of course the units ontology I wrote is only a small piece of what you are
> asking about, but none the less, I think it is an ontology by most common
> computer science definitions and is quite similar to the units ontology that
> you posted.  (Of course this begs the question of what is the difference
> between an ontology and a database schema - in general, my answer is 'not
> much'...  See for example p156 in Sowa's Knowledge Representation book)
> 
> I've checked in a slightly revised version of it, and also a new figure that
> includes the slot relationships that hopefully makes its structure clearer
> (I omitted them in the original for clarity).  I also isolated my attempt at
> describing measurements from its extension to ecological measurements in
> particular and called the ontology MeasurementBase.  It's in the same
> seek/projects/kr/ontologies folder as the Units ontology.  It includes the
> units ontology, and so gives a picture of how units relate to measurements
> etc.  There's a figure, MeasurementBase.gif, of the ontology.

I actually downloaded the ontology into Protege, and used Graphviz to view 
it :)  

I think it looks great.  I only have a few suggestions/questions...

It seems like the classes that end in "Concepts" are really meta classes
(and could probably go away). For example, Measurement and Measurement
Context are particular Measurement Concepts. In other words, if I have an
instance of a Measurement (e.g., 5 g/cm), it probably shouldn't be an 
instance of a Measurement Concept too (which is assumed by the IS-A).

Is ReferenceValue something specific to your Food Web application? I don't 
really understand what a referenced value signifies. 

It looks like you included RatioMeasurement as an IntervalMeasurement. It 
seems like it should have a property that further defines its units... or 
that it is created from two measurements?  How would Proportions and 
Densities/Concentrations be represented? 

It seems like Precision and Accuracy need to be related to a Measurement?


Shawn


> 
> Rich
>