Although the notion of the party family, with the various cross-national and cross-temporal similarities it implies, underlies much of the standard work on comparative party politics, it nevertheless remains one of the most undertheorized and least specified approaches to the general classification of parties. Four of the principal approaches that are used to identify party families are discussed: origins and sociology, transnational links, policy and ideology, and party name. The advantages and disadvantages of each approach are assessed, as are some of the more generic problems that may be associated with all four approaches. The two approaches that appear best suited to the specification and classification of party families are those based on the origin of parties and their ideology, but these should be developed in parallel rather than as alternatives. Both tap into what parties are rather than what parties do and hence are more likely to uncover core identities and shared political goals.
