Understanding implementation processes requires a research design that allows researchers to effectively engage with highly contingent processes.  This has led to a reliance on detailed examinations of single cases.  However, the strength of single unit case studies is also its biggest weakness in that these sort of studies provide little or no guidance as to which of the processes uncovered by the analysis are the most relevant or important.  Well-tested theory can overcome this problem, but in an interdisciplinary research area such as implementation, "there is a tendency to cite theory, but not apply it" (van der Heijden & Kuhlmann 2017:549) or, when particular theoretical approaches are applied, concept proliferation or concept stretching occurs because the existing theory is unable to fully explain empirical observations (van der Heijden & Kuhlmann 2017:546-7).  For policy practitioners, theoretical critiques of a particular policy are only of interest if they provide guidance on what can be done to increase the effectiveness of existing policies or programs.  This seminar will discuss the benefits of cross case comparisons;  the methodological issues facing implementation researchers; will briefly review existing approaches to comparative research using idiographic case studies or a combination of idiographic and nomethic case studies, before identifying a new methodological approach to studying implementation that has the potential to increase cross-case comparability whilst retaining a thick description of process.