Help! Parameter counting in POPAN for averaging

questions concerning analysis/theory using program MARK

Help! Parameter counting in POPAN for averaging

Postby CBardier » Tue Oct 04, 2016 1:27 am

Hello, I am fitting several models using the POPAN formulation to a data set (of frogs) with 10 encounter occasions (seasonal surveys along 3 years) and only one group. All models are built using PIMs and they are designed using the complete set of permutations (with repetition) of the following elements:

year
season
hot-cold season
breeding event
t
.

to test "all" posible hypothesis, resulting in 216 models like:

Phi(.) p(.) Pent(.)
Phi(year) p(hot-cold season) Pent(t)
Phi(.) p(t) Pent(year)
Phi(season) p(.) Pent(breeding event)
Phi(t) p(t) Pent(t)
aaand so on...

I want to average the best models and I have two groups of questions when it comes to counting parameters/confounding parameters:

1) As all examples of POPAN formulations in the MARK book are only with (.) and (t), I dont know how to apply the correction of the parameters to a model like Phi(.) p(t) Pent(year), how many parameters should I recognize in this example?

I think it should be 1 Phi, 10 p, 3 Pent (because there is one parameter per year) and 1 N, which gives 15 parameters... Then, as p(t) confounds parameters (related to first and last), should I count 2 less in this case (i.e. 13 parameters)?

2) Regarding to the parameter counting MARK does to a given model, and using the same example Phi(.) p(t) Pent(year), if MARK only recognizes 10 parameters, do I also have to correct this number (i.e. 8 parameters)? Or in which cases shoud I correct the parameters?

I read in chapter 4 about using the "threshold value" displayed in the output to determine which parameters are actually being counted by MARK. If I search, using the threshold value, which parameters were counted in the output, and see which of them are the confounding ones, not-counted parameters that are also confounding should be considered as already deleted?
However, sometimes less parameters than those lower than the threshold value are actually counted, and this also troubles me because I am not sure about what else makes a parameter not-countable.

Well... hope someone brings help, there's a thesis at risk!!

Thanks in advance,

C.
CBardier
 
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