Abstract
This paper is concerned with the processing of informal arguments, that is, arguments involving “probable truth.” A model of informal argument processing is presented that is based upon Hample's (1977) expansion of Toulmin's (1958) model of argument structure. The model postulates that a claim activates an attitude, the two components forming a complex that in turn activates reasons. Furthermore, the model holds occurrence of the reason, or possibly the claim and the reason, activates values. Three experiments are described that provide support for the model