[sc34wg3] Computed values in TMDM
Mon, 30 Jan 2006 08:29:44 -0500
Going throught the TMDM in hopes of writing the long awaited TMRM ->
TMDM mapping and I have a question about computed values.
4.1 Introduction says:
"Certain properties in the model are specified as computed properties,
which means that they are specified in terms of how their values *may*
be produced from other values in the model." (emphasis added)
Am I correct in assuming that computing the property is purely optional?
That is that if I wanted to (and I had the necessary information) I
could simply keyboard the value for any computed property? Or I could
compute the value?
The reason I ask is that I am trying to decide if "computed property" is
a constraint that the property value must be computed?
The constraint on the value of the property is clear.
What is unclear is what happens if I keyboard the value in but computing
the same value would produce a different result? Granted that would be
an invalid value but I don't see any mechanism to deal with that situation.
The merging procedure for all items appears to presume that the value is
*always* computed because it does not mention what to do if one or more
of the values were manually added and differed from each other or ones
that were computed. That is the item resulting from the merge is going
to have the computed properties, but which one, assuming there is one
that is different?
There are only two "computed" properties, [parent] and [roles played].
It is easier to see the issue with [roles played] but I don't see why it
could not also occur with [parent] due to poor keyyyboardinnng.
I grepped the list archives but did not come up with anything useful on
Hope everyone is at the start of a great week!
Chair, V1 - Text Processing: Office and Publishing Systems Interface
Co-Editor, ISO 13250, Topic Maps -- Reference Model
Member, Text Encoding Initiative Board of Directors, 2003-2005
Topic Maps: Human, not artificial, intelligence at work!