ABSTRACT
The multilevel regression model has become known in the research literature under a
variety of names, such as ‘random coefficient model’ (de Leeuw & Kreft, 1986;
Longford, 1993), ‘variance component model’ (Longford, 1987), and ‘hierarchical linear
model’ (Raudenbush & Bryk, 1986, 1988). Statically oriented publications tend to refer to
this model as a mixed-effects or mixed model (Littell, Milliken, Stroup & Wolfinger,
1996). The models described in these publications are not exactly the same, but they are
highly similar, and I will refer to them collectively as ‘multilevel regression models’.
