A Twitter Dataset on Tweets about People who Got Lost due to Dementia

This is the dataset used and analyzed in the paper "How can we Better Use Twitter to find a Person who Got Lost due to Dementia?".<br>A total of five tables are included. 1. raw_tweets.rds: All tweets that mentioned (i) "Dementia" or "Alzheimer"; and (ii) "Lost" or "Missing", which were crawled from Twitter from April to May 2017. 2. raw_userinfo.rds: The corresponding Twitter user info of Tweets.3. filtered_tweets.csv: Tweets that were included in the study. Details (age, gender, place, etc.) of the corresponding lost person mentioned in each tweet were appended in this table. 4. filtered_userinfo.csv: The corresponding Twitter user info of Tweets that were included in the study. Occupation (police / media / others) of each user were appended in this table. 5. cleansed_lostcases.csv: A cleansed table that shows several features of the lost cases.<br>