We can call the process whereby instrument settings are changed in the light of experience and new knowledge, while the overall goals and instruments of policy remain the same, a process of first order change in policy.
(Hall, 1993: 278)
… changes of this sort, when the instruments of policy as well as their settings are altered in response to past experience even though the overall goals of policy remain the same, might be said to reflect a process of second order change.
Finally…simultaneous changes in all three components of policy: the instrument settings, the instruments themselves, and the hierarchy of goals behind policy… occur relatively rarely, but when they do occur as a result of reflection on past experience, we can describe them as instances of third order change.
(Hall, 1993: 279)
Hall, P. 1993. Policy Paradigms, Social Learning, and the State: The Case of Economic Policymaking in Britain Comparative Politics Vol 25, (3), pp. 275-296. p277.
To be compared and contrasted with Advocacy Coalition Frameworks Deep Core Beliefs, Core Policy Beliefs and Secondary Aspects. See also “policy learning” and “social learning”