Fw: [Babase] Re: Request for Susan's input on SCI5 (fwd)

Karl O. Pinc babase@www.eco.princeton.edu
Thu, 21 Jul 2005 14:40:00 +0000


On 07/21/2005 04:35:54 AM, Amboseli Baboon Research Project wrote:

>> ...... We would then have 4 sorts of pregnancies.
>> 
>> 1) Ongoing pregnancies.  These have no associated biograph
>> row and so won't show up when you're looking at
>> BIOGRAPH.Birth to determine end-of-pregnancy date.
> 
> So Status = fetus would never apply to these. In fact they have no  
> status until they have a biograph row, right? Which is assigned at  
> birth or statdate?

You get a birth, and a bstatus, and a status, and a statdate
whenever somebody decides to create the biograph row.
I guess this is usually at birth.  I'm not sure I understand
the question.

>> 3) Observation abandoned during pregnancy.  On BIOGRAPH
>> the Status is "fetus" and the Birth = Statdate.
> 
> So if we terminate observation while mum is pregnant, it gets a row  
> in biograph with a birthdate = statdate and a status of fetus, and a  
> wide margin of error on bstatus, as with SCI5? Or what?

My thoughts per previous email are that the statdate would be
the last date of observation of the mom.  That would be
nice and accurate, and consistent.  As the system stands
then the birth would have to equal the statdate but now it occurs
to me that in this case we could go wild and allow the birth
to be _after_ the statdate.  In any case I think bstatus would
have to have a wide margin of error.  I do want a birth,
that's the whole point of the exercise -- to have some
sort of indicication of when the pregnancy ended.

(Of course, if there's reason to believe that the individual
was born and lived for some time then you can make birth
and statdate whatever is desired even though the individual
was never observed.  No doubt this has already been done
at some point, but it may have been done for the convenience
of the computer rather than because it that contributes
to the research utility of the database.  The approach
we're discussing here might be better.)

>>> > PREGS.
>> 
>> The trouble with this approach is it makes it hard to distingush
>> case 1, ongoing pregnancy, from case 3, observation abandoned.
> 
> Again, status = fetus would solve this I think.

Yes.  Cathrine and Jeanne don't seem to like the "fetus" approach.
(Cathrine suggested we change the name to "Unterminated pregnancy",
or "Pregnancy with undetermined ending" or something similar
to these that I can't recall.  I like these names better.)
I'm not clear on their objections to this approach.

Cathrine suggested a flag on the PREGS table to indiciate the
pregnancy state: in progress, unknown because observation terminated,
and terminated.  I've two problems with this.  First, the whole
point is to get a termination date for pregnancies.  I have not
reviewed the whole sexual cycle REPSTATS/CYCSTATS stuff but
am concerned about what happens when there's a pregnancy that
never ends, especially when it's followed by further cycling,
pregnancies, etc.  We put off the discussion until I investigate
further, particularly as regards we now have "gaps".
Anyhow, I believe that everything will be much simpler
and cleaner if pregnancies do have an ending that's always
recorded in the database, because they _will_ have to
have some sort of ending to make REPSTATS work.

Second I'm much in favor of having a single "model" that needs
to be understood, even when the model has depths to be
plumbed, rather than have multiple aproaches.  In this
case the "model" is that pregnancies
begin on D dates and end on birth dates.  Period.
When there's only one way to do it then there's no questions about
when things work this way and when they work that way.
The "fetus" approach extends the Biograph model from one
where biograph rows are made only after a pregnancy
terminates to one where biograph rows may, but are
not usually, entered for the individual _before_
the individual arrives in the world.  But it's still
the same model: one biograph row per individual.

Of course, the whole thing has to fit "in the real world"
so of course I'm willing to take whatever approach is
necessary.

Karl <kop@meme.com>
Free Software:  "You don't pay back, you pay forward."
                  -- Robert A. Heinlein