14,550 research outputs found
Thumbs up? Sentiment Classification using Machine Learning Techniques
We consider the problem of classifying documents not by topic, but by overall
sentiment, e.g., determining whether a review is positive or negative. Using
movie reviews as data, we find that standard machine learning techniques
definitively outperform human-produced baselines. However, the three machine
learning methods we employed (Naive Bayes, maximum entropy classification, and
support vector machines) do not perform as well on sentiment classification as
on traditional topic-based categorization. We conclude by examining factors
that make the sentiment classification problem more challenging.Comment: To appear in EMNLP-200
A Sentimental Education: Sentiment Analysis Using Subjectivity Summarization Based on Minimum Cuts
Sentiment analysis seeks to identify the viewpoint(s) underlying a text span;
an example application is classifying a movie review as "thumbs up" or "thumbs
down". To determine this sentiment polarity, we propose a novel
machine-learning method that applies text-categorization techniques to just the
subjective portions of the document. Extracting these portions can be
implemented using efficient techniques for finding minimum cuts in graphs; this
greatly facilitates incorporation of cross-sentence contextual constraints.Comment: Data available at
http://www.cs.cornell.edu/people/pabo/movie-review-data
Learning sentiment from students’ feedback for real-time interventions in classrooms
Knowledge about users sentiments can be used for a variety of adaptation purposes. In the case of teaching, knowledge about students sentiments can be used to address problems like confusion and boredom which affect students engagement. For this purpose, we looked at several methods that could be used for learning sentiment from students feedback. Thus, Naive Bayes, Complement Naive Bayes (CNB), Maximum Entropy and Support Vector Machine (SVM) were trained using real students' feedback. Two classifiers stand out as better at learning sentiment, with SVM resulting in the highest accuracy at 94%, followed by CNB at 84%. We also experimented with the use of the neutral class and the results indicated that, generally, classifiers perform better when the neutral class is excluded
Sentiment analysis:towards a tool for analysing real-time students feedback
Students' real-time feedback has numerous advantages in education, however, analysing feedback while teaching is both stressful and time consuming. To address this problem, we propose to analyse feedback automatically using sentiment analysis. Sentiment analysis is domain dependent and although it has been applied to the educational domain before, it has not been previously used for real-time feedback. To find the best model for automatic analysis we look at four aspects: preprocessing, features, machine learning techniques and the use of the neutral class. We found that the highest result for the four aspects is Support Vector Machines (SVM) with the highest level of preprocessing, unigrams and no neutral class, which gave a 95 percent accuracy
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Hierarchical classification for multiple, distributed web databases
The proliferation of online information resources increases the importance of effective and efficient distributed searching. Our research aims to provide an alternative hierarchical categorization and search capability based on a Bayesian network learning algorithm. Our proposed approach, which is grounded on automatic textual analysis of subject content of online web databases, attempts to address the database selection problem by first classifying web databases into a hierarchy of topic categories. The experimental results reported demonstrate that such a classification approach not only effectively reduces the class search space, but also helps to significantly improve the accuracy of classification performance
Rationale in Development Chat Messages: An Exploratory Study
Chat messages of development teams play an increasingly significant role in
software development, having replaced emails in some cases. Chat messages
contain information about discussed issues, considered alternatives and
argumentation leading to the decisions made during software development. These
elements, defined as rationale, are invaluable during software evolution for
documenting and reusing development knowledge. Rationale is also essential for
coping with changes and for effective maintenance of the software system.
However, exploiting the rationale hidden in the chat messages is challenging
due to the high volume of unstructured messages covering a wide range of
topics. This work presents the results of an exploratory study examining the
frequency of rationale in chat messages, the completeness of the available
rationale and the potential of automatic techniques for rationale extraction.
For this purpose, we apply content analysis and machine learning techniques on
more than 8,700 chat messages from three software development projects. Our
results show that chat messages are a rich source of rationale and that machine
learning is a promising technique for detecting rationale and identifying
different rationale elements.Comment: 11 pages, 6 figures. The 14th International Conference on Mining
Software Repositories (MSR'17
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