Abstract
Recently, emerging the notion of big data and social media has led us to enter data's big bang. Social networking services are widely used by people around the world, and they have become a part of major communication tools for all ages. Over the last decade, as online social networking sites become increasingly popular, companies tend to focus on advanced social media analysis for their marketing strategies. In addition to social media analysis, companies are mainly concerned about propagating of negative opinions on social networking sites such as Facebook and Twitter, as well as e-commerce sites. The effect of online word of mouth (WOM) such as product rating, product review, and product recommendations is very influential, and negative opinions have significant impact on product sales. This trend has increased researchers' attention to a natural language processing, such as a sentiment analysis. A sentiment analysis, also refers to as an opinion mining, is a process of identifying the polarity of subjective information and has been applied to various research and practical fields. However, there are obstacles lies when Korean language (Hangul) is used in a natural language processing because it is an agglutinative language with rich morphology pose problems. Therefore, there is a lack of Korean natural language processing resources such as a sentiment lexicon, and this has resulted in significant limitations for researchers and practitioners who are considering sentiment analysis. Our study builds a Korean sentiment lexicon with collective intelligence, and provides API (Application Programming Interface) service to open and share a sentiment lexicon data with the public (www.openhangul.com). For the pre-processing, we have created a Korean lexicon database with over 517,178 words and classified them into sentiment and non-sentiment words. In order to classify them, we first identified stop words which often quite likely to play a negative role in sentiment analysis and excluded them from our sentiment scoring. In general, sentiment words are nouns, adjectives, verbs, adverbs as they have sentimental expressions such as positive, neutral, and negative. On the other hands, non-sentiment words are interjection, determiner, numeral, postposition, etc. as they generally have no sentimental expressions. To build a reliable sentiment lexicon, we have adopted a concept of collective intelligence as a model for crowdsourcing. In addition, a concept of folksonomy has been implemented in the process of taxonomy to help collective intelligence. In order to make up for an inherent weakness of folksonomy, we have adopted a majority rule by building a voting system. Participants, as voters were offered three voting options to choose from positivity, negativity, and neutrality, and the voting have been conducted on one of the largest social networking sites for college students in Korea. More than 35,000 votes have been made by college students in Korea, and we keep this voting system open by maintaining the project as a perpetual study. Besides, any change in the sentiment score of words can be an important observation because it enables us to keep track of temporal changes in Korean language as a natural language. Lastly, our study offers a RESTful, JSON based API service through a web platform to make easier support for users such as researchers, companies, and developers. Finally, our study makes important contributions to both research and practice. In terms of research, our Korean sentiment lexicon plays an important role as a resource for Korean natural language processing. In terms of practice, practitioners such as managers and marketers can implement sentiment analysis effectively by using Korean sentiment lexicon we built. Moreover, our study sheds new light on the value of folksonomy by combining collective intelligence, and we also expect to give a new direction and a new start to the development of Korean natural language processing.
최근 다양한 분야에서 빅데이터의 활용과 분석에 대한 중요성이 대두됨에 따라, 뉴스기사와 댓글과 같은 비정형 데이터의 자연어 처리 기술에 기반한 감성 분석에 대한 관심이 높아지고 있다. 하지만, 한국어는 영어와는 달리 자연어 처리가 어려운 교착어로써 정보화나 정보시스템에의 활용이 미흡한 실정이다. 이에 본 연구는 감성 분석에 활용이 가능한 감성어 사전을 집단지성으로 구축하였고, 누구나 연구와 실무에 사용하도록 API서비스 플랫폼을 개방하였다(www.openhangul.com). 집단지성의 활용을 위해 국내 최대 대학생 소셜네트워크 사이트에서 대학생들을 대상으로 단어마다 긍정, 중립, 부정에 대한 투표를 진행하였다. 그리고 집단지성의 효율성을 높이기 위해 감성을 '정의'가 아닌 '분류'하는 방식인 폭소노미의 '사람들에 의한 분류법'이라는 개념을 적용하였다. 총 517,178(+)의 국어사전 단어 중 불용어 형태를 제외한 후 감성 표현이 가능한 명사, 형용사, 동사, 부사를 우선 순위로 하여, 현재까지 총 35,000(+)번의 단어에 대한 투표를 진행하였다. 본 연구의 감성어 사전은 집단지성의 참여자가 누적됨에 따라 신뢰도가 높아지도록 설계하여, 시간을 축으로 사람들이 단어에 대해 인지하는 감성의 변화도 섬세하게 반영하는 장점이 있다. 따라서 본 연구는 앞으로도 감성어 사전 구축을 위한 투표를 계속 진행할 예정이며, 현재 제공하고 있는 감성어 사전, 기본형 추출, 카테고리 추출 외에도 다양한 자연어 처리에 응용이 가능한 API들도 제공할 계획이다. 기존의 연구들이 감성 분석이나 감성어 사전의 구축과 활용에 대한 방안을 제안하는 것에만 한정되어 있는 것과는 달리, 본 연구는 집단지성을 실제로 활용하여 연구와 실무에 활용이 가능한 자원을 구축하여 개방하여 공유한다는 차별성을 가지고 있다. 더 나아가, 집단지성과 폭소노미의 특성을 결합하여 한글 감성어 사전을 구축한 새로운 시도가 향후 한글 자연어 처리의 발전에 있어 다양한 분야들의 융합적인 연구와 실무적인 참여를 이끌어 개방적 협업의 새로운 방향과 시사점을 제시 할 수 있을 것이라 기대한다.
