The article presents two models of public policy evaluation: one named idealistic and the other named pragmatic. In the former, social progress occurs when changes in the form of how society is organised bring us closer to social institutions and public authority conduct considered ideal. In the latter, social progress occurs if the prevailing social state (postchanges) is taken to be better than the previous social state (prechanges), according to certain pre-established judgement criteria. It is argued that the adoption of different models is one of the main obstacles to clarity in the public debate on the implementation of public policies, namely, that of making the points of disagreement explicit. The article presents a defence of the pragmatic model, which is considered more compatible with the use of scientific criteria in order to assess the effectiveness of policies.
