[Population Modeling] PopModWkGrpIMAG-news Digest, Vol 3, Issue 17

[Hunt, C. Anthony]

I offer some musings regarding defining population modeling (PM).
Population modeling is an activity.  For members of this group it is a
process with a purpose.  Identifying this group's PM process purposes will
help to define what PM means to us.

Given those purposes, the processes employed by members of this group are
drawn from a relatively specialized set of methods.  Identifying the
group's method's will further define what PM means to us.

Given those two constraints, I think that Merriam-Webster Unabridged
definitions of population are adequate (for our needs):

1 a :  the whole number of people or inhabitants occupying a specific
geographical locality (as an institution, a country, a world)
	[I might replace "people or inhabitants" with entities]
1 b :  the total number or amount of things especially within a given area

2 :  the act or process of populating
	[may apply only rarely]

3 a :  a body of persons having some quality or characteristic in common
and usually thought of as occupying a particular area
	[I might replace "persons" with entities, and (this is minor) "area" with
space]
3 b (1) :  the organisms inhabiting a particular area or biotope
3 b (2) :  a group of interbreeding biotypes that represents the level of
organization at which speciation begins

4 mathematics :  a group of individual persons, objects, or items from
which samples are taken for measurement statistically


-T-

On 1/17/15 2:06 AM, "popmodwkgrpimag-news-request at simtk.org"
<popmodwkgrpimag-news-request at simtk.org> wrote:

>Today's Topics:
>
>   1. Re: Population modeling definition (Jacob Barhak)
>
>
>----------------------------------------------------------------------
>
>Message: 1
>Date: Fri, 16 Jan 2015 04:07:08 -0600
>From: Jacob Barhak <jacob.barhak at gmail.com>
>Subject: Re: [Population Modeling] Population modeling definition
>To: Talitha Feenstra <talitha.feenstra at rivm.nl>
>Cc: popmodwkgrpimag-news at simtk.org
>Message-ID:
>	<CAM_y+3S_D1e1GhKA_8C8zvTeijA2_3nEupq61Jx1h-=s6mmGAA at mail.gmail.com>
>Content-Type: text/plain; charset="utf-8"
>
>Hi Talitha, Hi John, Hi Olaf, Hi Steve, Hi Stephan, Hi Al, and greeting to
>all others who have not participated yet.
>
>You have contributed thoughts to this discussion. I would like to point to
>two issues I see and add a third issue to the discussion
>
>1. Dictionary like definition:
>John and Olaf are trying to define the term like a dictionary. In this
>perspective, I myself would interpret population as: "A collection of X"
>where X can change as Madhav suggested before. It is probably a noun
>describing plurality of X.
>
>2. Definition by Models included:
>However, perhaps a more interesting discussion is what kind of models fall
>into our category. I recall Al and Steve trying to include Markov models,
>while Talitha and previously Stephan are excluding Markov Cohort models
>from falling within our definition of population modeling. This is to the
>best of my understating and I am surprised that Talitha suggested a strict
>definition since she some of her work is Markov model based.
>
>What would you all feel about including Markov models within population
>modeling only if they stratify the cohort by age, gender, and/or other
>parameters. And non stratified models will define these as cohort models
>outside population modeling?
>
>3. Modeling of individual uncertainty
>This is another question. Would we consider description of uncertainty of
>parameters in an individual within our population modeling group? For
>example, does defining distribution of height of a person by mean,
>variance, and distribution function fall into our category? After all we
>are modeling a single entity from information derived from a population. I
>would say yes, especially if the information is extracted from a
>population
>that we can name. But what about correlation between anthropometric
>features such as defining the mean ratio between height and arm length as
>one number? Will one number be sufficient  to call it population modeling
>or do we need a distribution? I would say if the number is associated to a
>population cohort then perhaps, and defiantly yes if we have several
>numbers associated with different population cohorts.
>
>I am interested to learn more what others think of those questions. I hope
>others will join this discussion.
>
>               Jacob