Clare Llewellyn


2016

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Homing in on Twitter Users: Evaluating an Enhanced Geoparser for User Profile Locations
Beatrice Alex | Clare Llewellyn | Claire Grover | Jon Oberlander | Richard Tobin
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

Twitter-related studies often need to geo-locate Tweets or Twitter users, identifying their real-world geographic locations. As tweet-level geotagging remains rare, most prior work exploited tweet content, timezone and network information to inform geolocation, or else relied on off-the-shelf tools to geolocate users from location information in their user profiles. However, such user location metadata is not consistently structured, causing such tools to fail regularly, especially if a string contains multiple locations, or if locations are very fine-grained. We argue that user profile location (UPL) and tweet location need to be treated as distinct types of information from which differing inferences can be drawn. Here, we apply geoparsing to UPLs, and demonstrate how task performance can be improved by adapting our Edinburgh Geoparser, which was originally developed for processing English text. We present a detailed evaluation method and results, including inter-coder agreement. We demonstrate that the optimised geoparser can effectively extract and geo-reference multiple locations at different levels of granularity with an F1-score of around 0.90. We also illustrate how geoparsed UPLs can be exploited for international information trade studies and country-level sentiment analysis.

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Improving Topic Model Clustering of Newspaper Comments for Summarisation
Clare Llewellyn | Claire Grover | Jon Oberlander
Proceedings of the ACL 2016 Student Research Workshop

2014

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Re-using an Argument Corpus to Aid in the Curation of Social Media Collections
Clare Llewellyn | Claire Grover | Jon Oberlander | Ewan Klein
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

This work investigates how automated methods can be used to classify social media text into argumentation types. In particular it is shown how supervised machine learning was used to annotate a Twitter dataset (London Riots) with argumentation classes. An investigation of issues arising from a natural inconsistency within social media data found that machine learning algorithms tend to over fit to the data because Twitter contains a lot of repetition in the form of retweets. It is also noted that when learning argumentation classes we must be aware that the classes will most likely be of very different sizes and this must be kept in mind when analysing the results. Encouraging results were found in adapting a model from one domain of Twitter data (London Riots) to another (OR2012). When adapting a model to another dataset the most useful feature was punctuation. It is probable that the nature of punctuation in Twitter language, the very specific use in links, indicates argumentation class.