Attribution of Quoted Speech in P ortuguese Text (2023)

Abstract: This paper describes and evaluates a rule-based system implementing a novel method for quote attribution in Portuguese text, working on top of a Constraint-Grammar parse. Both direct and indirect speech are covered, as well as certain other text- embedded quote sources. In a first step, the system performs quote segmentation and identifies speech verbs, taking into account the different styles used in literature and news text. Speakers are then identified using syntactically and semantically grounded Constraint-Grammar rules. We rely on relational links and stream variables to handle anaphorical mentions and to recover the names of implied or underspecified speakers. In an evaluation including both literature and news text, the system performed well on both the segmentation and attribution tasks, achieving F-scores of 98-99% for the former and 89-94% for the latter.

## evaluation with two main applications in mind, character cast extraction and information extraction, the system was evaluated on two very diverse sets of data, historical literature to cover the former, and news text to cover the latter. specifically, we used the first 7% of josé do patrocínio's "os retirantes", published in 1879 (13164 parser tokens, ca. 380 quotes), and a collection of articles foot_9 from the público newspaper covering the ukraine war between 3 august 2022 and 20 february 2023 (35076 parser tokens, ca. 610 quotes). in addition to extreme differences in vocabulary, syntax, style and orthography, there was a marked difference in quotation style, with 97.6% direct (speaker) quotes in "os retirantes" and 63.9% indirect foot_10 (source) quotes in the war news. the relative number of quoted sentences was higher in the literature sample, but the quotes were longer in the news text. ## conclusion we have shown how a rule-based and contextaware (cg) system can reliably exploit existing dependency and framenet annotation for quote attribution in portuguese, stressing the importance of long-distance referent links and the use of annotation-aware speaker and turntaking variables. given that the context conditions in the attribution rules make use of higher-level, universal linguistic categories and relations rather than language-specific vocabulary or morphology, it appears likely that the rules could be ported to other languages with similar base parser support. it is an added advantage of the approach that the same set of rules appears to work for both news and literature. for the news domain, with reallife information extraction in mind, future versions could exploit external resources to link ne mentions to unique identifiers and to resolve definite noun phrase mentions that are not clear from immediate context, e.g. for politicians and officials referenced with their function rather than their name.