In general, comparative legal studies can be divided into two main groups: macro-level comparison and micro-level comparison. While the former represents the comparison of two or more legal systems as a whole, the latter describes the analysis of a specific legal issue and how it is treated in two or more legal systems. Thus, if you compare the entire German and the US legal system, you do a macro-level comparison. If, on the other hand, you are interested in a juxtaposition of the ways contracts are made in the United States and Germany respectively, you would compare the two laws on a micro-level.
The macro-micro-level distinction, however, is only a cursory one. On the substantive side, the following five main groups of comparative legal studies have been distinguished:
- comparing one or more foreign legal system(s) with the domestic system;
- analyzing the solutions different legal systems offer for a legal problem;
- investigating the causal relationship between legal systems;
- contrasting the different stages of various legal systems; and
- examining the general legal evolution.
Overall, a comparative legal study requires a balanced and thorough analysis of two or more legal systems or some aspects thereof (as opposed to just mentioning the legal situation in a foreign country).
PETER DE CRUZ, COMPARATIVE LAW IN A CHANGING WORLD 7 and 227 (2nd ed. 1999).