what is the constraint in random effect can the random effect of an experiment only apply to a categorical variable? can random effects only apply to categorical variable can random effects be applied only to categorical variables can random effect only apply which variable can random effect only apply to can random effects apply to continuous variables? can random effects only apply to categorical variables why random effects can't be applied to categorical variables? can random effects only apply to categorical variables what type of variable can a random effect apply only to what is the random effect of categorical variables can a random effect apply to only categorical variables which variable has the most random effect which variables is a constant that has no random effect which variable is a random variable can random effects apply to a continuous variable? which statement is true about the possibility of random effect can random effect only apply to categorical variables? can random effect only apply to categorical variables?