The myriad of ways prediction has been considered in the scientific literature in the past highlights the need for a clear and inclusive definition. It is essential to be conceptually clear about what predictions are, one simple reason being that this is needed to establish what experimental evidence can be considered relevant and what not. First, prediction must be defined in such a way that what is called prediction is clearly about the future; environmental input which is likely to be upcoming or encountered soon.

This means that phenomena and processes that are retrospective or retrodictive, that is, utilize information to explain the past, should not more or less arbitrarily be called prediction. Second, prediction must be defined in an inclusive way such that phenomena and approaches that are clearly about the future are not more or less arbitrarily excluded from the discussion. In consideration of these requirements, prediction in the present book is defined as the conscious or subconscious use of information from previous experiences for the conscious or subconscious processing of information about future states of the body and environment.