Observed Data comments.

[John-Mark Gurney <jmg@newcontext.com>]

Hello,

Sorry for not getting this in sooner, but I have questions/comments
about the Observed Data object.

There is nothing in the spec that requires first_observed to be equal
to last_observed when number_observed is 1.

How is a tool who receives such an object to handle this?

In the case of when you don't know exactly when the observed data
was recorded, the _presision property added to first_observed can
convey this information correctly, and most acurately.

P.S. IMO, we should also make the number_observed default to 1, and
make it optional.  By setting a resonable default, we can reduce
the size of objects in common cases.

-- 
John-Mark