A Discourse Signal Annotation System for RST Trees
What it is about
The paper extends rstWeb, a browser tool for building Rhetorical Structure Theory trees, so that each relation in the tree can carry the signals that let a reader recognise it. A signal has four parts: the relation it supports, a possibly empty list of tokens (genre or layout signals have none), a type (discourse marker, semantic, syntactic, graphical, genre…) and a subtype (e.g. lexical chain, repetition). Earlier signal corpora either had no tree (PDTB) or did not anchor signals to tokens (the RST Signalling Corpus). On three re-annotated RST-SC documents (506 tokens, ~90 signals) the anchoring agreement rose from 86.0% / kappa 0.52 with a grid tool to 90.9% / 0.77 with the new interface. The tool was then used to add signals to the GUM corpus across eight genres.
Ideas
- I1. Record the signal of every link in Mova's frames, in the paper's four-part form: a
causeornextlink keeps the token(s) that produced it («because», «so», «and then», a purpose to) or a tokenless type (sentence order, a repeated entity). TodayFrame::howexplains roles butcause/nextare bare indices inprag/src/frames.rs.world frameswould print «cause→#1 [DM because]», and errors can be grouped by signal. - I2. With signals recorded, report cause and next precision per signal type on the frame bench (
world frames bench). Links from sentence order alone are expected to be the weakest; this tells whether to keep, restrict or drop them, with a number per type. - I3. Tokenless signals matter in tales too: a new paragraph, a quote ending, «Once upon a time». Add them as signal types of
nextand check how often the bench gold has anextlink across a paragraph break.
For Mova
36. Discourse relations and coherence §6 (connectives), §10 (segmentation and parsing), §11.1 (links between frames). Code: prag/src/frames.rs (link signal next to cause/next), prag/src/fbench.rs (per-signal scores). Measures: frame bench cause/next precision and recall by signal type. GUM's signal layer is NC: tests only.
Cite
@inproceedings{gessler2019discourse,
title = {{A Discourse Signal Annotation System for RST Trees}},
author = {Gessler, Luke and Liu, Yang and Zeldes, Amir},
booktitle = {Proceedings of the Workshop on Discourse Relation Parsing and Treebanking 2019},
year = {2019},
doi = {10.18653/v1/w19-2708},
url = {https://doi.org/10.18653/v1/w19-2708}
}References
- Table 1: Comparison with Liu and Zeldes (2019).* Lynn Carlson, Daniel Marcu, and Mary Ellen Okurowski. 2003. Building a discourse-tagged corpus in the framework of Rhetorical Structure Theory. In Current and New Directions in Discourse and Dialogue, Text, Speech and Language Technology 22, pages 85–112. Kluwer, Dordrecht. find our card
- Debopam Das and Maite Taboada. 2017. Signalling of coherence relations in discourse, beyond discourse markers. Discourse Processes, pages 1–29. find
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