Modelling complexity: Analysing between-individual and between-place variation - A multilevel tutorial

Geography is centrally concerned with difference and heterogeneity, yet much quantitative modelling has been concerned with finding average or general relationships thereby relegating variability to a single catchall 'error' term. Multilevel modelling, in contrast, anticipates complex between-individual and between-place heterogeneity. Previous accounts of the approach have stressed the modelling of higher level, between-place differences, but here the emphasis is placed on the simultaneous consideration of complex variation at all levels. A parade of models is presented each of which considers a particular facet of the model specification. Attention is drawn to the important contrasts between the modelling of categorical and continuous predictors. Illustrative results are provided for variations in British house prices, modelled with the MLn software. An appendix provides an example of the use of this software.