title: Public Trauma after the Sewol Ferry Disaster: The Role of Social Media in Understanding the Public Mood.
abstract: The Sewol ferry disaster severely shocked Korean society. The objective of this study was to explore how the public mood in Korea changed following the Sewol disaster using Twitter data. Data were collected from daily Twitter posts from 1 January 2011 to 31 December 2013 and from 1 March 2014 to 30 June 2014 using natural language-processing and text-mining technologies. We investigated the emotional utterances in reaction to the disaster by analyzing the appearance of keywords, the human-made disaster-related keywords and suicide-related keywords. This disaster elicited immediate emotional reactions from the public, including anger directed at various social and political events occurring in the aftermath of the disaster. We also found that although the frequency of Twitter keywords fluctuated greatly during the month after the Sewol disaster, keywords associated with suicide were common in the general population. Policy makers should recognize that both those directly affected and the general public still suffers from the effects of this traumatic event and its aftermath. The mood changes experienced by the general population should be monitored after a disaster, and social media data can be useful for this purpose.
authors.affiliation: School of Public Health, Seoul National University, Seoul 151-742, Korea. hkwoo@snu.ac.kr.|Institute of Health and Environment, Seoul National University, Seoul 151-742, Korea. hkwoo@snu.ac.kr.
authors.forename: Hyekyung
authors.initials: H
authors.lastname: Woo
authors.affiliation: School of Public Health, Seoul National University, Seoul 151-742, Korea. youngtae@snu.ac.kr.|Institute of Health and Environment, Seoul National University, Seoul 151-742, Korea. youngtae@snu.ac.kr.
authors.forename: Youngtae
authors.initials: Y
authors.lastname: Cho
authors.affiliation: School of Public Health, Seoul National University, Seoul 151-742, Korea. sey@snu.ac.kr.|Institute of Health and Environment, Seoul National University, Seoul 151-742, Korea. sey@snu.ac.kr.
authors.forename: Eunyoung
authors.initials: E
authors.lastname: Shim
authors.affiliation: Mining Laboratory, Daumsoft, Seoul 140-887, Korea. leekh@daumsoft.com.
authors.forename: Kihwang
authors.initials: K
authors.lastname: Lee
authors.affiliation: Mining Laboratory, Daumsoft, Seoul 140-887, Korea. kysong@daumsoft.com.
authors.forename: Gilyoung
authors.initials: G
authors.lastname: Song
mesh_terms: D004190:Disasters; D005260:Female; D006801:Humans; D008297:Male; D011593:Psychology, Social; D011639:Public Opinion; D056910:Republic of Korea; D061108:Social Media; D059020:Suicidal Ideation; D013405:Suicide / Q000523:psychology
keywords: Sewol ferry disaster; public mood; public trauma; social media; twitter