Robert Morris, Mike Nelson and Martin Fried, Installation Art and the Post-Medium Condition Claire Bishop argues that installation art is exemplary of 'post-medium specific art', in other words, art whose medium is so expanded that it no longer has much to do with traditional art historical genres such as sculpture and painting. She considers how the ascendency of 'post-medium art' in the 1960s is accompanied by a new emphasis on the first-hand experience of the viewer - and why it is through consideration of this viewer that installation art must be addressed, rather than through notions of expanded sculpture or site-specificity.Further ReadingRobert Morris, 'Notes on Sculpture 2', in Morris, Continuous Project Altered Daily, Cambridge, Mass: MIT Press, 1993, pp. 11-21.Brian O'Doherty, Inside the White Cube, the ideology of the gallery space (University of California Press, 1999), pp. 35-86.Reiss, Julie, From Margin to Center: The Spaces of Installation Art (MIT, 1999).