Argument Extraction from News

Proceedings of the 2nd Workshop on Argumentation Mining, pages 56–66, Denver, Colorado, June 4, 2015. c⃝2015 Association for Computational Linguistics Argument Extraction from News Christos Sardianos Dept. of Informatics and Telematics Harokopio University of Athens Omirou 9, Tavros, Athens, Greece sardianos@hua.gr Ioannis Manousos Katakis and Georgios Petasis and Vangelis Karkaletsis Institute of Informatics and Telecommunications National Centre for Scientific Research (N.C.S.R.) “Demokritos” GR-153 10, P.O. BOX 60228, Aghia Paraskevi, Athens, Greece {gkatakis, petasis, vangelis}@iit.demokritos.gr Abstract Argument extraction is the task of identifying arguments, along with their components in text. Arguments can be usually decomposed into a claim and one or more premises justifying it. The proposed approach tries to identify seg- ments that represent argument elements (claims and premises) on social Web texts (mainly news and blogs) in the Greek language, for a small set of thematic domains, including articles on poli- tics, economics, culture, various social issues, and sports. The proposed approach exploits distributed representations of words, extracted from a large non-annotated corpus. Among the novel aspects of this work is the thematic do- main itself which relates to social Web, in con- trast to traditional research in the area, which concentrates mainly on law documents and sci- entific publications. The huge increase of so- cial web communities, along with their user ten- dency to debate, makes the identification of ar- guments in these texts a necessity. In addition, a new manually annotated corpus has been con- structed that can be used freely for research pur- poses. Evaluation results are quite promising, suggesting that distributed representations can contribute positively to the task of argument ex- traction. 1 Introduction Argumentation is a branch of philosophy that studies the act or process of forming reasons and of drawing conclusions in the context of a discussion, dialogue, or conversation. Being an important element of human communication, its use is very frequent in texts, as a means to convey meaning to the reader. As a result, argumentation has attracted significant research focus from many disciplines, ranging from philosophy to ar- tificial intelligence. Central to argumentation is the notion of argument, which according to [Besnard and Hunter, 2008] is a set of assumptions (i.e. information from which conclusions can be drawn), together with a conclusion that can be obtained by one or more rea- soning steps (i.e. steps of deduction). The conclusion of the argument is often called the claim, or equiva- lently the consequent or the conclusion of the argu- ment, while the assumptions are called the support, or equivalently the premises of the argument, which provide the reason (or equivalently the justification) for the claim of the argument. The process of ex- tracting conclusions/claims along with their support- ing premises, both of which compose an argument, is known as argument extraction [Goudas et al., 2014] and constitutes an emerging research field. Nowadays, people have the ability to express their opinion with many different ways, using services of the social Web, such as comments on news, fora, blogs, micro-blogs and social networks. Social …

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