Data census of a geographically-bounded tweet set to enhance common operational picture tools

Location information is of particular importance to crisis informatics. The Twitter API provides several methods to assess a rough location and/or the specific latitude and longitude in which a post originated. This paper offers a comparison of location information provided by Twitter's four geolocation methods. The study aggregates one month of data from the greater Cincinnati, Ohio metropolitan area and assesses the relative contribution that each method can make to common operational picture tools used by crisis informatics researchers. Results show that of 49,744 Tweets, 4% contained geotags, 85.2% contained a location in the users' profile, and 3.5% contained no apparent location data, but were gathered using the bounding box method and would not have been identified using traditional methods of gathering data using geotagged Tweets or user profile information alone. We reflect on these results in light of design implications for common operational picture tools (COPs).