difference in factor level with r why does r use trt as the reference in mixed model what is the difference between trt and ph? what is the difference between th t and lh what is the function of trt in a mixed model how to test for differences between factors how to test the difference between trt, ls and hl in a mixed experiment? how to test for differences between factors what is the difference between trt and factor what is the difference between trt and llh in mixed model how do you test the significance of a mixed model? what is the difference in trt what is difference between trt and llm how to test for difference between two different factor models how to test for difference between two levels can you find the difference between a mixed model and a categorical variable? how to test the difference between two factors in a mixed model what is the difference between the two level of a mixed model how to test if trt level is difference what is the difference between a factor and a trt