Using UCDs as tags

[Roy Williams]

>  As far as I can
> tell, all efforts so far to define a dictionary of complete and unique
> terms have failed because it's very difficult.

Or maybe impossible? Can we really imagine defining science words in such a
close and accurate way that they can be compared by a computer, yet the
community of astronomers will agree to it? Does the word "planet" include
Pluto? What exactly does the word "image" mean?

> For the near term, as a
> temporary fix, we will be using UCDs but the UCD team are also
> not willing to take on the effort of making their dictionary unique
> or indeed complete.

We are trying to work towards a semantic net/ontology point of view. We
recognize that any astronomical measurement is specified by more than just a
UCD-type single word, but rather a host of meanings, reasons, and
connections. Further these may have different significances to different
people, to different applications.

Roy