Question: FO VS. FOCE VS. FOCE-INTER in POSTHOC 2014-1-3

Dear all, First of all, I wanna say HAPPY NEW YEAR to you guys. Best Wishes in this very beginning day of the "Horse Year"(Chinese calendar lol ) Well,as titled, here is the question: I'm now doing external validation of the PPK models pubished before by other groups with my own data. Ｉfind extreme differences in MPE(mean prediction error), RMSE(root of mean squared prediction error) and so on while using different estimation methods like FO, FOCE, or FOCE-INTER, especially the one with interaction from the former 2. I do understand the diversity in these 3 methods. But how much is the influence as to POSTHOC in external validation. For example: $ESTIMATION MAXEVAL=0 METHOD=1 NOABORT POSTHOC Could anybody explain to me and clarify the problem? Great thanks! Yours Zhao Chenyan Department of Clinical Pharmacy, Huashan Hospital, Fudan University, Shanghai, P.R.China