why are the assumptions of random error model dependent is the variable of tau_ij$ independent of the nd why do we test the variable for the variable for random effect model what is the nd of a random effect model that can be used to evaluate a variable? what is the independent random variable mean in a fixed effect model which model requires a variable nid to be independent why should i test a random effect model what is the generalized mean of a random effect random effect model is tau_epsilon_ij independent tau_ij is independent of what factor why do we need the independence assumption for random effect model why do we need the independence assumption for random effect if the random effect is independent why do we need the independence assumption of $tau_ij$ why we need the independence assumption for the single factor random effect model? which model is independent from fixed effect why do we need the independence assumption of $y_ij is a random effect model independent what is the difference between the fixed effect model and an independent model what is the independent variable of a fixed effect model