The work of [[Chris ArgyrisArgyros]] (1923-) describes the concept of '''double-loop learning''' (DLL) in which an individual, organization or entity is able, having attempted to achieve a goal on different occasions, to modify the goal in the light of experience or possibly even reject the goal. [[Single-loop learning]] (SLL) is the repeated attempt at the same problem, with no variation of method and without ever questioning the goal.