[R] Linear mixed model: question about t-values

Dear all, I have a question about the output of linear mixed model fitted in R using nlme package. In particular, what are the t-values that are given in an output, how are they calculated and based on what test? I guess it cannot be a simple Student t-test, otherwise how can the simple Student

[R] Linear mixed model: question about t-values

Dear all, I have a question about the output of linear mixed model fitted in R using nlme package. In particular, what are the t-values that are given in an output, how are they calculated and based on what test? I guess it cannot be a simple Student t-test, otherwise how can the simple Student t-