19,179 research outputs found
A Retrospective Analysis of the Fake News Challenge Stance Detection Task
The 2017 Fake News Challenge Stage 1 (FNC-1) shared task addressed a stance
classification task as a crucial first step towards detecting fake news. To
date, there is no in-depth analysis paper to critically discuss FNC-1's
experimental setup, reproduce the results, and draw conclusions for
next-generation stance classification methods. In this paper, we provide such
an in-depth analysis for the three top-performing systems. We first find that
FNC-1's proposed evaluation metric favors the majority class, which can be
easily classified, and thus overestimates the true discriminative power of the
methods. Therefore, we propose a new F1-based metric yielding a changed system
ranking. Next, we compare the features and architectures used, which leads to a
novel feature-rich stacked LSTM model that performs on par with the best
systems, but is superior in predicting minority classes. To understand the
methods' ability to generalize, we derive a new dataset and perform both
in-domain and cross-domain experiments. Our qualitative and quantitative study
helps interpreting the original FNC-1 scores and understand which features help
improving performance and why. Our new dataset and all source code used during
the reproduction study are publicly available for future research
Analyzing the Language of Food on Social Media
We investigate the predictive power behind the language of food on social
media. We collect a corpus of over three million food-related posts from
Twitter and demonstrate that many latent population characteristics can be
directly predicted from this data: overweight rate, diabetes rate, political
leaning, and home geographical location of authors. For all tasks, our
language-based models significantly outperform the majority-class baselines.
Performance is further improved with more complex natural language processing,
such as topic modeling. We analyze which textual features have most predictive
power for these datasets, providing insight into the connections between the
language of food, geographic locale, and community characteristics. Lastly, we
design and implement an online system for real-time query and visualization of
the dataset. Visualization tools, such as geo-referenced heatmaps,
semantics-preserving wordclouds and temporal histograms, allow us to discover
more complex, global patterns mirrored in the language of food.Comment: An extended abstract of this paper will appear in IEEE Big Data 201
Active learning in annotating micro-blogs dealing with e-reputation
Elections unleash strong political views on Twitter, but what do people
really think about politics? Opinion and trend mining on micro blogs dealing
with politics has recently attracted researchers in several fields including
Information Retrieval and Machine Learning (ML). Since the performance of ML
and Natural Language Processing (NLP) approaches are limited by the amount and
quality of data available, one promising alternative for some tasks is the
automatic propagation of expert annotations. This paper intends to develop a
so-called active learning process for automatically annotating French language
tweets that deal with the image (i.e., representation, web reputation) of
politicians. Our main focus is on the methodology followed to build an original
annotated dataset expressing opinion from two French politicians over time. We
therefore review state of the art NLP-based ML algorithms to automatically
annotate tweets using a manual initiation step as bootstrap. This paper focuses
on key issues about active learning while building a large annotated data set
from noise. This will be introduced by human annotators, abundance of data and
the label distribution across data and entities. In turn, we show that Twitter
characteristics such as the author's name or hashtags can be considered as the
bearing point to not only improve automatic systems for Opinion Mining (OM) and
Topic Classification but also to reduce noise in human annotations. However, a
later thorough analysis shows that reducing noise might induce the loss of
crucial information.Comment: Journal of Interdisciplinary Methodologies and Issues in Science -
Vol 3 - Contextualisation digitale - 201
Argumentation Mining in User-Generated Web Discourse
The goal of argumentation mining, an evolving research field in computational
linguistics, is to design methods capable of analyzing people's argumentation.
In this article, we go beyond the state of the art in several ways. (i) We deal
with actual Web data and take up the challenges given by the variety of
registers, multiple domains, and unrestricted noisy user-generated Web
discourse. (ii) We bridge the gap between normative argumentation theories and
argumentation phenomena encountered in actual data by adapting an argumentation
model tested in an extensive annotation study. (iii) We create a new gold
standard corpus (90k tokens in 340 documents) and experiment with several
machine learning methods to identify argument components. We offer the data,
source codes, and annotation guidelines to the community under free licenses.
Our findings show that argumentation mining in user-generated Web discourse is
a feasible but challenging task.Comment: Cite as: Habernal, I. & Gurevych, I. (2017). Argumentation Mining in
User-Generated Web Discourse. Computational Linguistics 43(1), pp. 125-17
Predicting the Vote Using Legislative Speech
As most dedicated observers of voting bodies like the U.S. Supreme Court can attest, it is possible to guess vote outcomes based on statements made during deliberations or questioning by the voting members. In most forms of representative democracy, citizens can actively petition or lobby their representatives, and that often means understanding their intentions to vote for or against an issue of interest. In some U.S. state legislators, professional lobby groups and dedicated press members are highly informed and engaged, but the process is basically closed to ordinary citizens because they do not have enough background and familiarity with the issue, the legislator or the entire process. Our working hypothesis is that verbal utterances made during the legislative process by elected representatives can indicate their intent on a future vote, and therefore can be used to automatically predict said vote to a significant degree. In this research, we examine thousands of hours of legislative deliberations from the California state legislature’s 2015-2016 session to form models of voting behavior for each legislator and use them to train classifiers and predict the votes that occur subsequently. We can achieve legislator vote prediction accuracies as high as 83%. For bill vote prediction, our model can achieve 76% accuracy with an F1 score of 0.83 for balanced bill training data
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