ehileman wrote:Hi Evan,
Thanks for the speedy reply!
In chapter 9 (section 9.3 of Program MARK: A Gentle Introduction, 17th ed.) the simulated example dataset (LD1.INP, copied below) uses two groups, marked as as young and marked as adults. The effective sample size for this dataset is 11,866, which is identical to the number of individuals marked as young. The number of individuals marked as adults is 11,861. Based on the reduced M-array, the number of individual live releases is actually 12,476.
Actually, you can't get the total number of released (which includes initial and subseuqnt) easily from the reduced m-array (although you can if you parse the full m-array output). If you look at the reduced m-array for the male dippers, and the table I posted, you'll see that the numbers used for ESS are not easily gleaned from the reduced m-array.
Unless I'm missing something (which I very well might be) or this is simply an odd coincidence, it seems that for Burnham's Joint live/dead model MARK is not using the total number of live releases as the effective sample size. Rather, MARK appears to be using the number of unique individuals from the largest group as the default setting effective sample size. Thoughts?
Eric
Well, the problem, perhaps, with that particular data set is that it has groups. I'd suggest simulating a single group -- and going from there. As per above, counting the number of 'releases' takes more work than you might wish for, if doing by hand. My assumption (based on a few years of experience) is that MARK is doing this correctly for you. But, worth simulating a small dataset, and confirming for yourself 'by hand'.
I still admit to guessing that the ESS for the live-dead is the same as for live only (since the way the saturated model likelihood for each is calculated under that assumption). But, I'll leave it to Gary to confirm.