Abstract

Perelman and Olbrechts-Tyteca's practical reasoning theory has attracted a great deal of interest since its publication in 1969. Their most important assertion, however, that argument is the logical basis for practical decision-making, has been under-utilized, primarily because it was not sufficiently operationalized for research purposes. This essay presents an operationalization of practical reasoning for use in analyzing argument logics that emerge through group interaction. Particular elements of discourse and argument are identified as responding to principles put forward by Perelman and Olbrechts-Tyteca, and are viewed as fitting together in a kind of logical argument structure that is well suited to the study of practical arguments in decision-making. Both the content elements and the logical argument structure are illustrated using examples from two studies examining decision logics in public participation and jury decision-making. Advantages of this approach and proposed recognition of a new `filtered' type of argument structure are discussed.