Program RELEASE GOF tests

questions concerning analysis/theory using program MARK

Program RELEASE GOF tests

Postby Otshawytscha » Mon Nov 20, 2006 12:46 pm

I'm interested in evaluating whether or not a survival difference exists between three release groups (~12,000 fish in each) and am in the process of evaluating the fit of my most global model (i.e., Phi(group*T), p(group*T)) prior to proceeding with formal model selection and inference. I have a very basic question regarding goodness-of-fit testing in this process....

What is the best way to proceed when component Test 2 and Test 3 Program RELEASE GOF tests have insufficient data (as indicated in output) and are nonsignificant (P>0.25 for all; also, overall tests and sums of Test 2 + Test 3 are nonsignificant)?

Thanks!
Otshawytscha
 
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Re: Program RELEASE GOF tests

Postby cooch » Mon Nov 20, 2006 1:25 pm

Otshawytscha wrote:I'm interested in evaluating whether or not a survival difference exists between three release groups (~12,000 fish in each) and am in the process of evaluating the fit of my most global model (i.e., Phi(group*T), p(group*T)) prior to proceeding with formal model selection and inference. I have a very basic question regarding goodness-of-fit testing in this process....

What is the best way to proceed when component Test 2 and Test 3 Program RELEASE GOF tests have insufficient data (as indicated in output) and are nonsignificant (P>0.25 for all; also, overall tests and sums of Test 2 + Test 3 are nonsignificant)?

Thanks!


Given your question, I *might* guess that you haven't read the relevant chapter (5) in the MARK book. Start there...
cooch
 
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Postby Otshawytscha » Tue Nov 21, 2006 1:55 pm

Thanks for the reply.

I have looked through both Chapter 5 of your book (a great resource, BTW) and Burnham et al.'s 'Blue Book'. Based on this, I haven't gained a clear sense of how to proceed in my situation. I've considered collapsing the final 2 encounter occasions into a single one (original: 1 release, 3 recapture events) to bolster detections, but I could not run RELEASE under these circumstances.....The other option I've considered was to collapse groups in the input file, but this is counter to the experimental objectives. :oops:
Otshawytscha
 
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Postby cooch » Tue Nov 21, 2006 3:28 pm

Otshawytscha wrote:Thanks for the reply.

I have looked through both Chapter 5 of your book (a great resource, BTW) and Burnham et al.'s 'Blue Book'. Based on this, I haven't gained a clear sense of how to proceed in my situation. I've considered collapsing the final 2 encounter occasions into a single one (original: 1 release, 3 recapture events) to bolster detections, but I could not run RELEASE under these circumstances.....The other option I've considered was to collapse groups in the input file, but this is counter to the experimental objectives. :oops:


Then you've missed one of the basic points - RELEASE tests a fully time-dependent model. If you are getting contingency tables that are to sparse to be interpreted in any robust way, your only defensible option is to use a less general model - you can retain your groups, but just consider a model without time-dependence.

If you do that, you'll need to use something other than RELEASE, as discussed in detail in Chapter 5.
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