Figure 1

Examples of the visualisations of call detail records used by human labellers to determine whether it could be accurately estimated whether and when someone migrated to Dar es Salaam. The estimated move date is depicted by the pink hyper-plane. Each graph is a different individual, and each translucent dot represents a mobile phone call. The black triangle denotes a call made from the University of Dar es Salaam’s campus. All examples were labelled as correctly identifying migration to Dar es Salaam, with the exception of F which was deemed to have too large of an overlap due to what looks like regular commuting before migrating