Observation data model comments - UML jargon

[Martin Hill]

>>Concerning the schema, I don't understand why you have inheritance
>>between ObsData and MeasuredQuantities and not an historical
>>(processing) link.
> 
> You are probably right, I don't fully understand UML as you can see, but I
> am not sure everyone else does either so I am not quite sure which
> model style to copy.... Logically I agree with you, I just don't quite see
> how to represent it.

What's a historical (processing) link?  If you're saying that one 'has' 
the other then a straight line with no extra bits will do.  If a 
MeasuredQuantity 'is a kind of' ObsData (or v.v.) then one with an open 
arrow is right.

If you're saying that one might become the other, or is related due to 
some other process, then no line should be in the class diagram.  There 
are other UML diagrams (activity) to describe processes and such; I'll 
have a look and see what might be the easiest for newcomers .


-- 
Martin Hill
www.mchill.net
07901 55 24 66