A corpus analysis of discourse relations for Natural Language Generation

We are developing a Natural Language Generation (NLG) system that generates texts tailored for the reading ability of individual readers. As part of building the system, GIRL (Generator for Individual Reading Levels), we carried out an analysis of the RST Discourse Treebank Corpus to find out how human writers linguistically realise discourse relations. The goal of the analysis was (a) to create a model of the choices that need to be made when realising discourse relations, and (b) to understand how these choices were typically made for “normal” readers, for a variety of discourse relations. We present our results for discourse relations: concession, condition, elaboration additional, evaluation, example, reason and restatement. We discuss the results and how they were used in GIRL

Better Document-level Sentiment Analysis from RST Discourse Parsing

Discourse structure is the hidden link between surface features and document-level properties, such as sentiment polarity. We show that the discourse analyses produced by Rhetorical Structure Theory (RST) parsers can improve document-level sentiment analysis, via composition of local information up the discourse tree. First, we show that reweighting discourse units according to their position in a dependency representation of the rhetorical structure can yield substantial improvements on lexicon-based sentiment analysis. Next, we present a recursive neural network over the RST structure, which offers significant improvements over classification-based methods.Comment: Published at Empirical Methods in Natural Language Processing (EMNLP 2015

The Language of Rights: Towards an Aristotelian-Thomistic Analysis

Alasdair MacIntyre has argued that our contemporary discourse about “rights,” and “natural rights” or “human rights,” is alien to the thought of Aristotleand Aquinas. His worry, it seems, is that our contemporary language of rights is often taken to imply that individuals may possess certain entitlement-conferringproperties or powers entirely in isolation from other individuals, and outside the context of any community or common good. In thispaper, I accept MacIntyre’s worries about our contemporary language of “rights”; however, I seek to show that some of our contemporary language or discourseabout “justice” and “rights” is not altogether misguided, but does—in fact—reflect a properly critical understanding of what is meant by“justice” and “rights.

Semantic Unification A sheaf theoretic approach to natural language

Language is contextual and sheaf theory provides a high level mathematical framework to model contextuality. We show how sheaf theory can model the contextual nature of natural language and how gluing can be used to provide a global semantics for a discourse by putting together the local logical semantics of each sentence within the discourse. We introduce a presheaf structure corresponding to a basic form of Discourse Representation Structures. Within this setting, we formulate a notion of semantic unification --- gluing meanings of parts of a discourse into a coherent whole --- as a form of sheaf-theoretic gluing. We illustrate this idea with a number of examples where it can used to represent resolutions of anaphoric references. We also discuss multivalued gluing, described using a distributions functor, which can be used to represent situations where multiple gluings are possible, and where we may need to rank them using quantitative measures. Dedicated to Jim Lambek on the occasion of his 90th birthday.Comment: 12 page

A discourse analysis of e-mail messages in a Malaysian Business Community

The study attempts to investigate recurrent grammatical features and functions of electronic mail discourse in a selected business community, comprising executives in a Malaysian public limited company. It also examines whether the electronic mail system has influenced language forms in the executives' e-mail discourse. Differences between language in the e-mail discourse and language in conventional business writing are explored too. The corpus comprises 102 electronic mail messages from the executives' routine communication in work contexts. The study examines grammatical features, communicative functions and discourse features of the messages. Findings reveal a predominance of main clauses in imperative and declarative moods, and subordinate clauses denoting purpose and reason, reflecting that e-mail communication of the community is used more for requesting and informing, and less for enquiring. Other discourse features like opening salutation, opening statement, closing statement and closing salutation are also found in the e-mail messages although they are not compulsory for such a communication. It is hoped that the language features and functions, and other discourse features identified in the e-mail communication of the business community would contribute towards pedagogy and course design for English for Business Communication, as well as for e-mail communication at the workplace