Mark Sprevak is a Research Fellow in Philosophy at King's College, Cambridge, UK. His research interests are in philosophy of mind, language, and metaphysics. His research is focused on metaphysical problems surrounding the notion of computation. He is currently interested in whether computation can be a mind-independent feature of the world, or whether the conditions under which a system performs a computation contain ineliminable reference to an observer. The answer to this question is important because it has implications for computational theories of mind and cognitive science.