The early twenty-first century has seen contemporary art make continued use of audience participation, in which the spectator becomes part of the artwork itself. In this book, Kaija Kaitavuori claims that the `participator' is a new artistic role that does not fall under the auspices of artist or spectator and in proving such she devises a four-group typology of involvement. Her classification distinguishes between different forms of engagement and identifies their specific features. The key criteria she proposes are how concepts of authorship and ownership shift in relation to collectively created work, how contracts regulating the use and production of shared work are arranged and the extent to which involvement in making art can be regarded as democratic. This highly original book thus offers students and teachers the tools with which to improve their understanding of participatory art and removes the confusing terminology that has characterised so many other discussions.