epSpread - Storyboarding for visual analytics

We present epSpread, an analysis and storyboarding tool for geolocated microblogging data. Individual time points and ranges are analysed through queries, heatmaps, word clouds and streamgraphs. The underlying narrative is shown on a storyboard-style timeline for discussion, refinement and presentation. The tool was used to analyse data from the VAST Challenge 2011 Mini-Challenge 1, tracking the spread of an epidemic using microblogging data. In this article we describe how the tool was used to identify the origin and track the spread of the epidemic.