Hi, I am new to R (and not really a stats expert) and am having trouble interpreting its output. I am running a human learning experiment, with 6 scores per subject in both the pretest and the posttest. I believe I have fitted the correct model for my data- a mixed-effects design, with subject as a random factor and session (pre vs post) nested within group (trained vs control). I am confused about the output. The summary command gives me this table: > D.lme<- lme(score~GROUP/session, random=~1|subject, data=ILD4L ) > summary(D.lme) Linear mixed-effects model fit by REML Data: ILD4L Subset: EXP == "F" AIC BIC logLik -63.69801 -45.09881 37.84900 Random effects: Formula: ~1 | subject (Intercept) Residual StdDev: 0.1032511 0.1727145 Fixed effects: score ~ GROUP/session Value Std.Error DF t-value p-value (Intercept) 0.10252778 0.05104328 152 2.008644 0.0463 GROUPT 0.09545347 0.06752391 12 1.413625 0.1829 GROUPC:sessionpost -0.00441389 0.04070919 152 -0.108425 0.9138 GROUPT:sessionpost -0.23586042 0.03525520 152 -6.690090 0.0000 Correlation: (Intr) GROUPT GROUPC GROUPT -0.756 GROUPC:sessionpost -0.399 0.301 GROUPT:sessionpost 0.000 -0.261 0.000 Standardized Within-Group Residuals: Min Q1 Med Q3 Max -2.66977386 -0.52935645 -0.08616759 0.57215015 3.26532101 Number of Observations: 168 Number of Groups: 14 I believe the fixed-effects section of this output to be telling me that my model intercept (which I assume to be the control group pretest?) is significantly different from 0, and that GROUPT (i.e. the trained group) does not differ significantly from the intercept- therefore no pretest difference between groups? The next line is, I believe showing that the GROUPC x sessionpost interaction (i.e., control posttest scores?) is not significantly different from the intercept (i.e. control pretest scores). Finally, I am interpreting the final line as indicating that the GROUPT x sessionpost interaction (ie, trained posttest scores?) is significantly different from the trained pretest scores (GROUPT). A treatment contrast that I would like to apply would be for Control-post vs Trained-post, to see if the groups differ after training, but I'm not sure how to do this- and I feel I am probably overcomplicating the matter. also, I am confused about how to report this output in my publication. For instance, what should I be reporting for df? Those found on the output of the anova table? Would it be possible to look through this for me and indicate how to interpret the R output, and also how I should be reporting this? Apologies for asking such basic questions, but I would like to start using R more regularly and to make sure I am doing so correctly. Many thanks, Dan