Preferred Argument Structure For Discourse Understanding

The main purpose of communication is to exchange information. Any discourse understanding model should be able to process the flow of information throughout the entire text. According to Du Bois (1987)'s studies of information flow in discourse across a number of languages, information distribution among argument positions in clauses is by no means random, but certain grammatical patterns tend to recur consistently. He thus formulated a Preferred Argument Structure (PAS) for the preferential structural configurations of arguments. In our examination of Chinese narrative discourse, the language also displays PAS, yet the Chinese PAS challenges the universality of the one Du Bois proposed. Based on the quantity and distribution of lexical arguments and new referents across grammatical roles in discourse, it is realized that Chinese PAS also maintains one new argument at most within a basic information processing unit. Since new referents in Chinese have to be encoded in full NP form, it is thus less likely to have more than one lexical argument within a clause. Moreover, this single new argument appears preferentially in the O role, rather than the A and S roles Du Bois's PAS formulates.Since the structure of information flow has a corresponding grammatical patterning, both grammatical and pramatic processing can be carried out simultaneously, in that the information status of an argument can be identified by virtue of grammatical analysis. Although PAS is neither universal nor categorical, it can function in a discourse understanding model as heuristic device to process the information structure of a connected spoken discourse.