Quantitative empirical research into legal decisions must be conducted using statistical tools that are appropriate for the data involved. Court decisions are one example of a domain where the data is intrinsically hierarchical (i.e., multilevel), since decisions are made on individual cases by decision-makers in courts located across geographical (or jurisdictional) areas. Past research into court decisions has often either neglected higher level variables or incorrectly used single-level statistical models to analyze multilevel data. The lack of a clear understanding about when and why multilevel statistical models are required may have contributed to this situation. In this paper, we identify the problems of estimating single-level models on hierarchically structured data, and consider the advantages of conducting multilevel analyses under these circumstances. We use the example of criminal sentencing research to illustrate the arguments for the use of multilevel models and against a single-level approach. We also highlight some issues to be addressed in future sentencing studies.

This article examines the main assumptions and theoretical underpinnings of case study method in legal studies. It considers the importance of research design, including the crucial roles of the academic literature review, the research question and the use of rival theories to develop hypotheses and the practice of identifying the observable implications of those hypotheses. It considers the selection of data sources and modes of analysis to allow for valid analytical inferences to be drawn in respect of them. In doing so it considers, in brief, the importance of case study selection and variations such as single or multi case approaches. Finally it provides thoughts about the strengths and weaknesses associated with undertaking socio-legal and comparative legal research via a case study method, addressing frequent stumbling blocks encountered by legal researchers, as well as ways to militate them. It is written with those new to the method in mind.