Mining location from social media: A systematic review

During the last ten years, a large body of research extracting and analysing geographic data from social media has developed. We analyse 690 papers across 20 social media platforms, focussing particularly on the method used for extraction of location information. We discuss and compare extraction methods, and consider their accuracy and coverage. While much work has adopted location information in the form of coordinates in message metadata, this approach has very limited coverage in most platforms and reports on posting location rather than message location or the location that the message refers to (geofocus). In contrast, a wide array of other approaches have been developed, with methods that extract place names from message text providing the highest accuracy. Methods that use social media connections also provide good results, but all of the methods have limitations. We also present analysis of the range and frequency of use of different social media platforms, and the wide range of application areas that have been addressed. Drawing on this analysis we present a number of future areas of research that warrant attention in order for this field of research to mature.