Dear all,       I have built 5 models for 4 subjects. Now I use the Bayesian Model Selection provided by SPM8 to select the optimal one. I made use of  the "batch" function and enter all sessions of all subjects. After running the batch, first using  Fixed Effect, then Random Effect, the BMS.mat file gives the results of ffx and rfx. ffx results include F value for each model of each subject, SF value for each model, and P value  for each model. rfx results include, in addition to F and SF, which are the same with those of ffx, an alpha value, an exp_r value and an xp value for each model. What do these parameters mean? How can I get the Bayesian Factor (for each model relative to another), the BIC and AIC value? Thank you very much!