Acceso usuarios
Héctor Castro Mosqueda, Antonio Rico Sulayes 
This paper employs lexical analysis tools, quantitative processing methods, and natural language processing procedures to analyze language samples and identify lexical items that support automatic topic detection in natural language processing. This paper discusses how keyword extraction, a technique from corpus linguistics, can be employed in obtaining features that improve automatic classification; in particular, this research is concerned with extracting keywords from a corpus obtained from social networks. The corpus consists of 1,841,385 words and is subdivided into three sub-corpora that have been categorized according to the topic of the comments in each one of them. These three topics are violence against women, violence against the LGBT community, and violence in general. The corpus has been obtained by scraping comments from YouTube videos that address issues such as street harassment, femicide, feminist movements, drug trafficking, forced disappearances, equal marriage, among others. The topic detection tasks performed with the corpus extracted from the social media showed that the keywords rendered a 98% accuracy when classifying the collection of comments from 51 videos, as one of the three categories mentioned above, and 92% when classifying almost 7,500 comments individually. When keywords were removed from the classification task and all words were used to perform the classification task, accuracy dropped by an average of 17%. These results support the argument for keyword relevance in automatic topic detection.
