Algorithmic complexity

Algorithmic complexity provides a mathematical formal notion of string complexity. Building on this, one arrives at mathematical “gold standard” (though incomputable) definitions of randomness, induction, similarity and even intelligence. These definitions can be turned into practical algorithms by using common compressors to approximate the universal solutions. One can consider the theories as idealized cognition with respect to which one can aim to describe actual biological cognition by listing biases and limitations that need to be defined relative to some normative reference.