[Babase] "On" vs "By" sexual maturity dates & Tdate maturity
markers
Susan Alberts
babase@www.eco.princeton.edu
Thu, 27 Oct 2005 13:11:04 -0400
>Susan, maybe you could answer this. If not would
>you please draw Jeanne's attention?
I called Jeanne and told her to read this.
>
>I assume that when female's have a "By" date then their
>first Tdate need not be their assigned maturity date, it could
>be sometime after. Right?
This is correct according to my understanding.
>
>This plays into Jeanne's comments on the documentation
>where she seems to assume that maturity dates will
>have some sort of Bstatus like plus-or-minus X years
>time range. If I'm reading her comments right.
>I don't think we want this.
My understanding is that mature dates will be definite. They will
either be ON or they will be BY. We will only use the ON to estimate
age at attainment. We can use both ON and BY to identify age sex
classes at any given time.
There is a question of how we deal with the fact that some ON dates
have larger margins of error than others. I think that we have a
large enough sample of these for now that we can afford to be picky
and only use dates that have a narrow margin of error. This would
mean that all dates that now have an E attached to them (for
estimated) in the current (FoxPro) version of babase would become BY
dates and would never be used to estimate age at attainment of the
marker in question.
>
>I seem to recall arriving at the conclusion that all
>maturity dates are definite -- even though some
>simply set a definite upper bound. This sounds
>good. And it seems ok that those that are not
>exact need not be exactly on a Tdate.
This agrees with my understanding.
>
>If it turns out we do want some rough estimate of
>when maturity happened I'd say that's a different
>bit of data and we should leave the current
>maturity date design alone and add to it to
>get more information. A phone call would be
>required I think.
>
OK. I am inclined to leave the option open at the moment. In other
words I don't see a strong need to build it into the system right
now, given that we can do so later if we want to. Jeanne?
Susan
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--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Susan Alberts, Associate Professor
Department of Biology, Duke University, Box 90338, Durham NC 27708
phone 919-660-7272 fax 919-660-7293