608 research outputs found
Lexical Normalization of Spanish Tweets with Rule-Based Components and Language Models
This paper presents a system to normalize Spanish tweets, which uses preprocessing rules, a domain-appropriate edit-distance model, and language models to select correction candidates based on context. The system is an improvement on the tool we submitted to the Tweet-Norm 2013 shared task, and results on the task's test-corpus are above-average. Additionally, we provide a study of the impact for tweet normalization of the different components of the system: rule-based, edit-distance based and statistical
Dialectometric analysis of language variation in Twitter
In the last few years, microblogging platforms such as Twitter have given
rise to a deluge of textual data that can be used for the analysis of informal
communication between millions of individuals. In this work, we propose an
information-theoretic approach to geographic language variation using a corpus
based on Twitter. We test our models with tens of concepts and their associated
keywords detected in Spanish tweets geolocated in Spain. We employ
dialectometric measures (cosine similarity and Jensen-Shannon divergence) to
quantify the linguistic distance on the lexical level between cells created in
a uniform grid over the map. This can be done for a single concept or in the
general case taking into account an average of the considered variants. The
latter permits an analysis of the dialects that naturally emerge from the data.
Interestingly, our results reveal the existence of two dialect macrovarieties.
The first group includes a region-specific speech spoken in small towns and
rural areas whereas the second cluster encompasses cities that tend to use a
more uniform variety. Since the results obtained with the two different metrics
qualitatively agree, our work suggests that social media corpora can be
efficiently used for dialectometric analyses.Comment: 10 pages, 7 figures, 1 table. Accepted to VarDial 201
A modular approach for lexical normalization applied to Spanish tweets
Twitter is a social media platform with widespread success where millions of people continuously
express ideas and opinions about a myriad of topics. It is a huge and interesting source of data but most
of these texts are usually written hastily and very abbreviated, rendering them unsuitable for traditional
Natural Language Processing (NLP). The two main contributions of this work are: the characterization of
the textual error phenomena in Twitter and the proposal of a modular normalization system that
improves the textual quality of tweets. Instead of focusing on a single technique, we propose an extensible
normalization system that relies on the combination of several independent ‘‘expert modules’’, each
one addressing an very specific error phenomenon in its own way, thus increasing module accuracy and
lowering the module building costs. Broadly speaking, the system resembles to an ‘‘expert board’’: modules
independently propose correction candidates for each Out of Vocabulary (OOV) word, rank the candidates
and the best one is selected. In order to evaluate our proposal, we perform several experiments
using texts from Twitter written in Spanish about a specific topic. The flexibility of defining resources at
different language levels (core language, domain, genre) combined with the modular architecture lead to
lower costs and a good performance: requiring a minimal effort for building the resources and achieving
more than 82% of accuracy compared to the 31% yielded by the baseline.Ministerio de EconomÃa y Competitividad TIN2012-38536-C03-02Junta de AndalucÃa P11-TIC-7684 M
Multilingual sentiment analysis in social media.
252 p.This thesis addresses the task of analysing sentiment in messages coming from social media. The ultimate goal was to develop a Sentiment Analysis system for Basque. However, because of the socio-linguistic reality of the Basque language a tool providing only analysis for Basque would not be enough for a real world application. Thus, we set out to develop a multilingual system, including Basque, English, French and Spanish.The thesis addresses the following challenges to build such a system:- Analysing methods for creating Sentiment lexicons, suitable for less resourced languages.- Analysis of social media (specifically Twitter): Tweets pose several challenges in order to understand and extract opinions from such messages. Language identification and microtext normalization are addressed.- Research the state of the art in polarity classification, and develop a supervised classifier that is tested against well known social media benchmarks.- Develop a social media monitor capable of analysing sentiment with respect to specific events, products or organizations
Multilingual sentiment analysis in social media.
252 p.This thesis addresses the task of analysing sentiment in messages coming from social media. The ultimate goal was to develop a Sentiment Analysis system for Basque. However, because of the socio-linguistic reality of the Basque language a tool providing only analysis for Basque would not be enough for a real world application. Thus, we set out to develop a multilingual system, including Basque, English, French and Spanish.The thesis addresses the following challenges to build such a system:- Analysing methods for creating Sentiment lexicons, suitable for less resourced languages.- Analysis of social media (specifically Twitter): Tweets pose several challenges in order to understand and extract opinions from such messages. Language identification and microtext normalization are addressed.- Research the state of the art in polarity classification, and develop a supervised classifier that is tested against well known social media benchmarks.- Develop a social media monitor capable of analysing sentiment with respect to specific events, products or organizations
TweetNorm: a benchmark for lexical normalization of spanish tweets
The language used in social media is often characterized by the abundance of informal and non-standard writing. The normalization of this non-standard language can be crucial to facilitate the subsequent textual processing and to consequently help boost the performance of natural language processing tools applied to social media text. In this paper we present a benchmark for lexical normalization of social media posts, specifically for tweets in Spanish language. We describe the tweet normalization challenge we organized recently, analyze the performance achieved by the different systems submitted to the challenge, and delve into the characteristics of systems to identify the features that were useful. The organization of this challenge has led to the production of a benchmark for lexical normalization of social media, including an evaluation framework, as well as an annotated corpus of Spanish tweets-TweetNorm_es-, which we make publicly available. The creation of this benchmark and the evaluation has brought to light the types of words that submitted systems did best with, and posits the main shortcomings to be addressed in future work.Postprint (published version
Workshop Proceedings of the 12th edition of the KONVENS conference
The 2014 issue of KONVENS is even more a forum for exchange: its main topic is the interaction between Computational Linguistics and Information Science, and the synergies such interaction, cooperation and integrated views can produce. This topic at the crossroads of different research traditions which deal with natural language as a container of knowledge, and with methods to extract and manage knowledge that is linguistically represented is close to the heart of many researchers at the Institut für Informationswissenschaft und Sprachtechnologie of Universität Hildesheim: it has long been one of the institute’s research topics, and it has received even more attention over the last few years
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