After discussing diverse concepts of types or syndromes the definition of types, according to configural frequency analysis (CFA), is given. A type, in this theory, is assumed to be a configuration of categories belonging to different attributes. This configuration should occur with a probability which is higher than the conditional probability for given univariate marginal frequencies. The conditional probability is computed under the null hypothesis of independence of the attributes. Types are identified by simultaneous conditional binomial tests and interpreted by means of an interaction structure analysis in a multivariate contingency table. Two further versions of CFA are explained. By prediction CFA it is possible to predict certain configurations by other ones while by c-sample CFA it is possible to discriminate between populations by means of configurations. The procedures are illustrated by an example concerning the responses of patients to lumbar punctures.