Open form assumed that no artistic expression is complete until it has been appropriated by its users or beholders. In the following decades, the concept became a key principle of performance and film art, and led to the development of process-oriented and interdisciplinary artistic techniques. Hansen’s concept revolutionized the traditional means of artistic communication. The book includes in-depth interviews with some of the most important protagonists of experimental art in Poland, who investigate the historical impact of the open form. Other contributions comment on the theory’s influence on a younger generation of artists. Visual material by Hansen and the artists complete this extensive volume.