Factors influencing the implicitation of discourse relations across languages

Relations that hold between discourse segments can, but need not, be made explicit by means of discourse connectives. Even though the explicit signaling of discourse relations is optional, not all relations can be easily conveyed implicitly. It has been proposed that readers and listeners have certain expectations about discourse and that discourse relations that are in line with these expectations (default) are more often implicit than the ones that are not (non-default). In this paper, we analyze the implicitation of discourse relations from a multilingual perspective. Using an annotation scheme for discourse relations based on Sanders, Spooren, & Noordman (1992), we distinguish between default and non-default discourse relations to predict the amount of implicit translations per relation in parallel corpora from four language pairs. We argue that the existing hypotheses about reader expectations are not sufficient to explain default discourse relations and propose that the rate of implicitation of discourse relations is governed by cognitive complexity: default discourse relations are cognitively simple within the framework of basic categories of discourse relations.