In accordance with the objectives of the research program, the societal as well as the normative conditions of the issues under study are examined. Hence, both the empirical methods of data collection typical of the social sciences and the research methods of criminal law science – especially comparative law – are employed.
The analytical methods of the social sciences are employed primarily in the Department of Criminology. Because the Department of Criminology studies problems of social change from a criminological and the Department of Criminal Law similar problems from a normative perspective, and because the focuses of the two departments – each with its own accents and emphases – are complementary, the Department of Criminal Law enjoys synergy effects on its research program from the research conducted by the Department of Criminology in its program.
Comparative criminal law takes center stage in the study of criminal law-related issues. A broadly inclusive comparison of criminal law is often necessary in order to obtain a thorough understanding of current legal developments. This is because it may not be possible – due to global processes in criminal and legal policy – to achieve a good grasp of local and regional developments if a comprehensive normative picture of the developments occurring around the world and of the connections among these developments is lacking. In some of the Institute’s projects, it may be necessary to carry out an analysis of the applicable law by means of a systematic and/or a case-based comparison that – by applying techniques developed to aid in the comparison and evaluation of systems of law (wertende Rechtsvergleichung) – also addresses the social and legal foundations underlying the rules. On this basis, then, general legal principles can be developed that, by means of wertende Rechtsvergleichung, close existing loopholes in European and international criminal law. From a practical perspective, criminal policy approaches developed in this manner support the identification of the best possible solution by way of the "benchmarking" of various criminal policy models. Because of these interrelationships, comparative criminal law in the research program of the Department of Criminal Law is not only a research method but is also, in and of itself, a central research topic and research focus.
In order to pull together the prerequisites, methods, and capabilities of comparative criminal law, the third – method-oriented – research focus in the program addresses the development of a theory of comparative criminal law. The goal is to develop a universal doctrine of criminal law on this basis. Due to the global challenges and developments in criminal law, the construction of the doctrine’s system, its concepts, and the determination of its fundamental values and models are targeted at deriving globally applicable findings for international comparative problems that give rise to an “international grammar of criminal law” and – in the European Union – to a "common European criminal law system."
These methodological issues of comparative criminal law and the concept of a universal criminal law doctrine are being studied in the research program particularly in a major long-term project: the Max Planck Information System for Comparative Criminal Law – also known as the "virtual institute."