Games with a Purpose (GWAPs) make it possible to collect data or solve problems that are too complex or too costly in terms of means to be solved by machines.These fun activities, which represent a type of serious gaming, are delicate to design since they must be both appealing and useful.

This book presents and analyzes GWAPs with specific themes (biology, medicine, automatic language processing, etc.). It develops, more particularly, the project JeuxDeMots, a set of GWAPs, the objective of which is to construct a large lexical knowledge base with the help of games. The study of these different concepts allows us to define the criteria that are important to favor during the design of a GWAP in order to create an efficient tool for the acquisition of useable data or the resolution of problems.