On predicting and improving the quality of Volunteer Geographic Information projects

Initiatives that rely upon the contributions of volunteers to reach a specific goal are growing more and more with the success of Web 2.0–interactive applications.Also scientific projects are testing and exploiting volunteers’collaboration,but the quality of information obtained with this approach is often puzzling.This paper offers a rich overview of many scientific projects where geographic contributions are committed to volunteers,to the aim of defining strategies to improve information quality.By describing real examples of Volunteer Geographic Information(VGI),the contribution establishes a categorization based on the characteristics of the information,tasks,and scopes of the projects.After a discussion on the relationships of categories and VGI quality,the paper analyses techniques to improve the quality of volunteered information according to the moment of its assessment(i.e.,ex ante,ex post,or both with respect to information creation).The paper outlines the main limitations of the different approaches and indicates some guidelines for future developments.