Multi-document Summarization System Using Rhetorical Information

Abstract

Over the past 20 years, research in automated text summarization has grown significantly in the field of natural language processing. The massive availability of scientific and technical information on the Internet, including journals, conferences, and news articles has attracted the interest of various groups of researchers working in text summarization. These researchers include linguistics, biologists, database researchers, and information retrieval experts. However, because the information available on the web is ever expanding, reading the sheer volume of information is a significant challenge. To deal with this volume of information, users need appropriate summaries to help them more efficiently manage their information needs. Although many automated text summarization systems have been proposed in the past twenty years, none of these systems have incorporated the use of rhetoric. To date, most automated text summarization systems have relied only on statistical approaches. These approaches do not take into account other features of language such as antimetabole and epanalepsis. Our hypothesis is that rhetoric can provide this type of additional information. This thesis addresses these issues by investigating the role of rhetorical figuration in detecting the salient information in texts. We show that automated multi-document summarization can be improved using metrics based on rhetorical figuration. A corpus of presidential speeches, which is for different U.S. presidents speeches, has been created. It includes campaign, state of union, and inaugural speeches to test our proposed multi-document summarization system. Various evaluation metrics have been used to test and compare the performance of the produced summaries of both our proposed system and other system. Our proposed multi-document summarization system using rhetorical figures improves the produced summaries, and achieves better performance over MEAD system in most of the cases especially in antimetabole, polyptoton, and isocolon. Overall, the results of our system are promising and leads to future progress on this research.