Is Measurement a Black Box? On the Importance of Understanding Measurement Even in Quantum Information and Computation

It has been argued, partly from the lack of any widely accepted solution to the measurement problem, and partly from recent results from quantum information theory, that measurement in quantum theory is best treated as a black box. However, there is a crucial difference between ‘having no account of measurement’ and ‘having no solution to the measurement problem’. We know a lot about measurements. Taking into account this knowledge sheds light on quantum theory as a theory of information and computation. In particular, the scheme of ‘one‐way quantnum computation’ takes on a new character in light of the role that reference frames play in actually carrying out any one‐way quantum comptuation.