This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
The Museum of Modern Art defines installation in a single spare sentence, as an art form that comprises visual elements in any medium and the space they inhabit. The second half of that definition carries the weight, because the inclusion of space is precisely what divides installation from the sculptural tradition it grew out of. A traditional sculpture, however dynamic its form, is a fixed object that the viewer walks around. The environmental work reverses this: it no longer confronts the spectator as an object but surrounds the spectator, who moves within it as within a stage set, a garden or an interior. Installation art is large-scale, mixed media construction, often made for a specific place or a temporary period, that offers a complete unified experience rather than a display of separate, individual artworks. The materials follow from that ambition: miscellaneous materials, light and sound have remained fundamental to the form, and environmental art pursues concreteness by including more of reality itself, real clothes, actual objects, actual lighting effects and real items of furniture, rather than by representing reality more accurately. Works in major museum collections show the range this allows, from James Turrell's light work Frontal Passage of 1994 to Pipilotti Rist's video environment Ever Is Over All of 1997 and Sarah Sze's Triple Point of 2013. The deepest consequence concerns the audience. Because the work is a space, the visitor's body is inside the medium, and the visitor's movement and attention become material the artist composes with. Ilya Kabakov, the form's most influential theorist and practitioner, stated the principle directly: the main actor in the total installation, the main center toward which everything is addressed, is the viewer. Whether this makes installation an offshoot of sculpture, as some critics still hold, or a category of its own, the practical test is simple. If removing the surrounding space would leave the work intact, it is sculpture. If the space is the work, it is an installation.