If someone is interacting with an interactive art installation, what is their role? Are they part audience, part artist? Are they still just an audience, or do terms like audience and artist cease to make sense in such cases?

A great question. It has never been the case that the role of'artist' and 'viewer' have been as clear cut as we would like. Firstof all, historically, many 'artists' were anonymous craftspeople whoprobably worked collaboratively -- and collaborative art works havereturned more recently as an important category within the art world.Second, in the 20th century, many artists experimented withstrategies designed to introduce either randomness into their works,or allow their 'unconscious' selves to be expressed.

On the side of the viewer, we tend to think of the viewer asindividual, and as neutral. By 'neutral' I mean not adding anythingto the work or contributing anything to its meaning. But bothconcepts are clearly ideal situations, at best. Theatrical works, forexample, rely upon the viewers being a crowd and moreover behaving asa crowd. Related, a great deal of philosophical work has pursued theidea that the 'reception' of the work is not to be located in anindividual or group of individuals, but is a historical phenomenon. Awork of art designed to shock an audience in 1910 is no longer foundshocking -- if the 'shock' was part of the work originally, then itis difficult to avoid the conclusion that the work of art has beenchanged by the change in its viewers. Similarly, the neutrality ofthe viewer is questionable, since individual likes and dislikes, andmore importantly different types of background knowledge, willgreatly influence the event of viewing. So, for example, a Medievalreligious fresco will be an entirely different object for a casualtourist as for an expert in iconography.

So, arguably at least, the situation you describe with respect toinstallation art is just an exacerbation of, or a making explicit of,what was already the case: the work of art is not primarily aphysical object, but is rather an event of some kind.

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