Book excerpt: Viewers of contemporary art are often invited to involve themselves actively in artworks, by entering installations, touching objects, performing instructions, or clicking on interactive websites. Why have artists sought to engage spectators in these new forms of participation? In what ways does active participation affect the viewer's experience and the status of the artwork? Spanning a range of practices, including kinetic art, happenings, environments, performance, installations, relational and new media art from the 1950s to the present, this critical anthology sheds light on the history and specificity of artworks that only come to life when you – the viewer - are invited to "do it yourself." Rather than a specialist topic in the history of twentieth- and twenty-first century art, the "do-it-yourself" artwork raises broader issues concerning the role of the viewer in art, the status of the artwork, and the socio-political relations between art and its contexts.