There is a need for some clarification, as a crucial role of Evaluation Units or Departments or Evaluation Studies is to draw lessons from evaluations and to facilitate the process of applying those lessons. The following definition is offered as a basis for discussion:

A "lesson learned" (LLE), in the context of evaluations, can be defined as a generalization based on an experience (e.g., projects, policies or programmes) which was evaluated.

Note that "lessons learned" are not merely "experience". A LLE is the outcome of a learning process, which involves reflecting upon the experience. Neither an accumulation of "facts" or "findings" nor an accumulation of evaluations will, by itself, yield lessons. The lessons have to be produced (distilled or extracted) from the experience.

A distinction can be made between

normative (or instrumental) lessons, concerning what should be done (or what should be avoided) and

causal lessons, which correspond to statements of the form "if...then..", showing what are the likely outcomes of different processes.

Until some years ago, it was common practice in evaluations to refer to findings, conclusions and recommendations, but not so much to "lessons learned". Thus, it is worthwhile to ask the following question:

What are the differences between findings, recommendations and lessons learned?

a finding is a "factual statement" (such as "the repayment rate was 95%"; but any description involves a selection)

a conclusion is a synthesis of "factual statements" corresponding to a specific circumstance (e.g., policy x failed to achieve its objectives)

a recommendation is a prescription on what should be done in a specific circumstance (for example, in order to increase the repayment rate in a certain credit project).

a lesson learned is a generalization which does not refer to a specific circumstance but to a class of situations (for example, to credit projects for the rural poor in the highlands). It points out what is very likely to happen and/or on what should be done in order that something will take place (or to prevent it).

It should be noted that the LLE can be helpful in the process of formulating recommendations and, more generally, in the design process. As observed above, "Lessons learned" are (or might be) an output of evaluations, and they are (or should be) also an input in the design process. To facilitate this linkage of evaluation to design (of policies, programmes and/or projects), as well as to help in the retrieval and use of lessons learned, it is convenient to elaborate a typology of situations to which the lessons learned might apply.