Discourse Relations and Relevance Implicatures: A Case Study

In this paper, we discuss dependencies between rhetorical discourse structure and relevance implicatures. We follow [3] and infer relevance implicatures from the assumption that an answer provides optimal information for solving an explicitly or implicitly given decision problem of the inquirer. Such a decision problem can be identified with a question raised in the conversation. Background questions not only depend on explicit questions under discussion but may also be raised by rhetorical relations such as Concession or Contrast. In this paper, we are especially concerned with implicatures of embedded questions. We show by some examples that determining the rhetorical relation that connects two text spans and setting up a pragmatic model that explains the implicatures of embedded sentences interact with each other.