After fitting a model with lme, I run post-hoc tests with glht (with specific hypotheses specified in ph_conditional, and not multiple comparisons). The results are repored in the following:
> lev.ph <- glht(lev.lm, linfct = ph_conditional); > summary(lev.ph, test=adjusted("bonferroni")) Simultaneous Tests for General Linear Hypotheses Fit: lme.formula(fixed = data ~ des_days, data = data_red_trf, random = ~des_days | ratID, method = "ML", na.action = na.omit, control = lCtr) Linear Hypotheses: Estimate Std. Error z value Pr(>|z|) des_days1 == 0 3232.2 443.2 7.294 9.05e-13 *** des_days14 == 0 3356.1 912.2 3.679 0.000702 *** des_days48 == 0 2688.4 1078.5 2.493 0.038025 *
I am trying to understand the output values. How are the z-scores computed? If the function uses standard errors, shouldn't these be t-statistics (and not z-scores)?
Thanks for your help, and sorry for the perhaps trivial question.