what is mixed model for symmetry can covariance structure for a random random effect what is mixed model covariance what kind of covariance pattern do you use for random intercepts what is the purpose of a mixed model what is meant by mixed random effects with covariance pattern what is the difference between fixed effects and random intercepts why would you specify residual covariance in mixed effects models what is the difference between a fixed and random intercept what is the difference between a random intercept and an autoregressive pattern in a mixed model can you specify a random intercept in a mixed-effects model? which type of covariance structure can be specified for a fixed effect? what is the difference between a mixed and random effect model what are the different models of random effects what's the difference between a random intercept of the variable and a covariance pattern what is random intercept in mixed effects can i use random random intercept in mixed effect models? can you specify random intercept can you specify a random intercept as a residual in a mixed effects linear algebra can you use a randomly selected covariance pattern?