ABSTRACT
This chapter shows that Paul Diesing's five types of substantive reasoning are Technical rationality, Economic rationality, Legal rationality, Social rationality and Political rationality. System transformation draws upon all five of Diesing's rationalities but particularly requires engaging with legal, social and political rationalities. The chapter discusses three types of models that were direct delivery and provision of commodities and services, behavior change for improved outcomes, and using systems to strengthen good outcomes. Development agencies in particular are still some way from understanding the full implications of doing good by moving from technical proficiency to system transformation. The chapter explores the opportunities for evaluations to be useful in each of these models including attending to the risks and moral hazards as sociated with each; doing good almost always includes the potential for harm even to the intended beneficiary. The bundle of rationalities involved in each of these three approaches differs. Understanding this allows us to get more rapidly to useful evaluation questions.
