ABSTRACT
To this point, we have focused on multilevel models in which a single measurement is made on each individual in the sample, and these individuals are in turn clustered. However, as mentioned in Chapter 2, multilevel modeling can be used in a number of different contexts, with varying data structures. In particular, this chapter will focus on using the multilevel modeling framework to analyze longitudinal data. Longitudinal data occur when a series of measurements are made on each individual in the sample, usually over some period of time.
