Crowdsourcing, Citizen Science or Volunteered Geographic Information? The Current State of Crowdsourced Geographic Information

Citizens are increasingly becoming an important source of geographic information,sometimes entering domains that had until recently been the exclusive realm of authoritative agencies.This activity has a very diverse character as it can, amongst other things, be active or passive, involvespatial or aspatial data and the data provided can be variable in terms of key attributes such asformat, description and quality. Unsurprisingly, therefore, there are a variety of terms used todescribe data arising from citizens. In this article, the expressions used to describe citizen sensingof geographic information are reviewed and their use over time explored, prior to categorizingthem and highlighting key issues in the current state of the subject. The latter involved a review of~100 Internet sites with particular focus on their thematic topic, the nature of the data and issues suchas incentives for contributors. This review suggests that most sites involve active rather than passivecontribution, with citizens typically motivated by the desire to aid a worthy cause, often receiving littletraining. As such, this article provides a snapshot of the role of citizens in crowdsourcing geographicinformation and a guide to the current status of this rapidly emerging and evolving subject.