In linguistics, the comparative is a syntactic construction that serves to express a comparison between two (or more) entities or groups of entities in quality, or degree. See comparison (grammar) for an overview of comparison, as well as positive and superlative degrees of comparison.
Comparative politics is a field in political science, characterized by an empirical approach based on the comparative method. In other words, comparative politics is the study of the domestic politics, political institutions, and conflicts of countries. It often involves comparisons among countries and through time within single countries, emphasizing key patterns of similarity and difference. Arend Lijphart argues that comparative politics does not have a substantive focus in itself, but rather a methodological one: it focuses on "the how but does not specify the what of the analysis." In other words, comparative politics is not defined by the object of its study, but rather by the method it applies to study political phenomena. Peter Mair and Richard Rose advance a slightly different definition, arguing that comparative politics is defined by a combination of a substantive focus on the study of countries' political systems and a method of identifying and explaining similarities and differences between these countries using common concepts. Rose states that, on his definition: "The focus is explicitly or implicitly upon more than one country, thus following familiar political science usage in excluding within-nation comparison. Methodologically, comparison is distinguished by its use of concepts that are applicable in more than one country."