Sometimes referred to as volunteered geographic information (VGI) or user-generated content (UGC), crowdsourced data is contributed by nonauthoritative sources (e.g., everyday citizens). The challenge for GIS practitioners is to ensure the usability of this data in a GIS workflow or to turn this crowdsourced data into useful geographic knowledge. This can mean checking the data to make sure that it is correct. It can also mean getting involved in data collection; structuring the process to ensure that the collected data has meaning and is appropriate as well as accurate.
Long the keepers of purely authoritative data, GIS practitioners are beginning to take crowdsourced data seriously. Crowdsourcing gives ordinary citizens the opportunity to provide feedback directly to the government. It can significantly augment authoritative datasets. It provides extraordinary opportunities for citizen science. And it can put a virtual "army" of volunteers on a large project in short order.
GIS tools supporting crowdsourcing will change the way organizations collect and manage spatial data. New features in ArcGIS 10 give users the ability to modify geographic content within any Web mapping application and provide a venue for online communities to become active contributors to geodatabases. Web editing makes it easy to capture ideas and observations for distributed problem solving and extend GIS editing capabilities to more people within the organization. These capabilities allow everyone—from authoritative data editors to citizens on the street—to contribute content to the geodatabase. This will enrich GIS, giving GIS practitioners new types of data to use, manage, interpret, and incorporate into their work.