Solo shows include ICA, London (1984), Irish Museum of Modern Art , Dublin, Ireland (1993), Whitechapel Gallery , London (2001), Kunstmuseum Wolfsburg , Wolfsburg, Germany (2001), Hasselblad Center, Göteborg, Sweden (2002), Astrup Fearnley Museum, Oslo, Norway (2004) and retrospectives at Schaulager , Basel (2005), Tate Modern (2005) and MoMA , New York (2007), Art Institute of Chicago (2007), SFMoMA, San Francisco (2008), Tamayo Museum , Mexico City and Vancouver Art Gallery , Vancouver (2008), and Staatliche Kunstsammlungen, Dresden (2010). Wall was also included in documentas 10 and 11. 
It is true that much medium analysis essentializes, but critical or theoretical discourse involving medium is not necessarily essentializing. It may seem that the modernist tradition, for example, supports Carroll’s contention that use of artistic medium is necessarily essentializing, since exploration of an art form by means of its media often meant stripping away all that could be in order to discover what was essential to the art form. However, the modernist question of what is essential to the art form is itself a particular, historically-located question about artistic medium, and whatever answers modernist artists generated need not be taken as definitive of the timeless and unchanging essence of some particular art form. In fact, rejection of essentializing claims is revealed as necessary for sound medium analysis, since there is no independent grasp on what counts as an artistic medium outside of the context provided by a particular artistic problem or concern. This can be somewhat obscured for us because of the importance of modernism for our understanding of artistic medium as a concept; it is characteristic of modernist artists to take an art form itself as a question or problem to be explored. The modernist question of what, for example, constitutes the conditions of painting is part of an artistic project that takes as its starting point the history of painting and looks to inherit that tradition by stripping away all that is inessential to painting. But modernist artists and critics identify and explore shape or surface or color as they arise as problems or conditions for painting at a particular historical moment, not because of some timeless understanding they have of the nature of the media as such.