bootstrap and 2species model

questions concerning analysis/theory using program PRESENCE

bootstrap and 2species model

Postby Cris » Mon Jun 29, 2009 12:06 pm

Dear friends,
I’m running a two-species analysis with PRESENCE, I’m trying to apply bootstrapping to get better estimation of parameters. However, if I run the same model with and without bootstrapping the output files are exactly the same. Why there are not differences? Probably I’m doing something wrong but I don’t know what, anyone can help me?

Thanks a lot!
Cris
 
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bootstrap and 2species model

Postby jhines » Mon Jun 29, 2009 12:23 pm

Hi Chris,

The bootstrapping option is not programmed into PRESENCE at the moment. I should have disabled the option in the user-interface when the 2-species model is selected.

Jim
jhines
 
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bootstrap and 2species model

Postby jhines » Mon Jun 29, 2009 3:13 pm

Chris,

A way to get bootstrap variances if you're using a standard model (no covariates) would be to use GENPRES to simulate data and generate a spreadsheet of estimates, which could be averaged.

Jim
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