Hello again

I'm still in the early learning process of PRESENCE but I would appreciate some advice before I spend too much more time racking my brain trying to get this to work with my data. I would like to compare the detectability of two different methods, I have 285 sites, 4 surveys, method 1 is more much effective at detecting the species than method 2 so as a result some of the columns for the method 2 only have a few "1"'s and lots of "0"'s. I've been trying to run the multi method analysis on my data but despite my best efforts I keep getting numerical convergence although its always greater than the recommended minimum value in the FAQ's so not necessarily a huge problem, but in addition, one of my theta values and SE's are ridiculously high.... for example....

A4 theta3 : 25.540412 126178.322551

A5 theta4 : 0.287754 0.787783

If I run the data for the two methods separately using the single season analysis, I don't have this issue with numerical convergence. I am a little confused as to how the theta should be interpreted in the multi method analysis as looking at previous posts it seems that what is in the help file does not appear to be entirely accurate. So I have a few questions:

1) Should I just analysis the data separately and discuss the differences between the two methods without actually comparing them directly. Are there any issues with this?

2) Can I continue to model the data using the multi-method with this large theta value, and if so, how can I justify doing this?

3) Can I adjust the theta parameters at all to overcome this issue?

Thanks for any advice

Kerry