What is Multilevel Modelling? Why Use a Multilevel Model?

Multilevel modelling is a technique for dealing with grouped or clustered data. Multilevel modelling can also be used to examine data with repeated measures. For example, if we are monitoring the blood pressure of a patient group on a regular basis, the subsequent measures might be thought of as being grouped within the individual subjects. It is capable of handling data with varying measurement times from one element to the next. In such instances, a multilevel model in ML can be used to simulate the parameters that change at more than one level.