The purpose of this article is to present a parametrised functional interpretation. Depending on the choice of the two parameters one obtains well-known functional interpretations, among others Gödel\u27s Dialectica interpretation, Diller-Nahm\u27s variant of the Dialectica interpretation, Kreisel\u27s modified realizability, Kohlenbach\u27s monotone interpretations and Stein\u27s family of functional interpretations. We show that all these interpretations only differ on two basic choices, which are captured by the parameters, namely the choices of (1) "how much" of the counter-examples for A becomes witnesses for the negation of A, and of (2) "how much" information about the witnesses of A one is interested in