Remember that the residuals are the difference between our predicted reading score based on these characteristics and the actual reading score we see in the data.

If you violate it, you get incorrect estimations of the standard errors.

The assumption of independence means that cases in our data should be independent of one another,

independent variables are measured without error.

the sample used in the analysis is representative of its population.

relationship between the independent and dependent variable is linear.

Multilevel modeling is an extension of OLS.

Additionally, we can look at how Level 1 predictors interact with each other and how Level 2 predictors interact with each other.

Perhaps most importantly, we are also able to do cross-level interactions so that we can explain how Level 1 predictors affect our dependent variable according to different contexts (Level 2 predictors).