Explanation

From EvaluationWiki

An explanation of why an evaluand operates well or badly, is something entirely different from determining whether it operates well or badly, i.e., an evaluation of it. An evaluator may undertake to provide such an explanation, and clients often request it or expect it, but the evaluator must understand the difference and the extra effort and data required to support this kind of explanation by comparison with the evaluation. This distinction between evaluation and explanation, overlooked by advocates of theory-driven evaluation who think the two are essentially connected, is proven by the importance of black-box evaluation where no explanation is available but evaluation proceeds without a problem. But it is complicated by two explanatory elements that can legitimately occur in good evaluation. The first of these is the basic kind of explanation that is a legitimate part of an evaluation, namely a non-committal explanation of how the evaluand appears or is said to operate, which can be seen as part of the description of the evaluand, a normal part of the evaluation report, and often part of the description of the evaluand that is provided by the client to the evaluator. The second element occurs in some analytic evaluations, the kind referred to as component evaluations, where, if one does take on this approach to the assignment, one evaluates the whole by evaluating its parts, and hence to some extent may be able to explain the performance of the whole in terms of the behavior of its parts. Since neither of these approaches is essential to evaluation-there are good alternatives-the explanations they involve are not a sign that explanation if a necessary part of evaluation. And it always requires more expertise and resources, especially time, than the alternatives, in return for which it produces something extra for the client. As long as evaluators realize they do not have to provide explanations of the evaluand's operation in order to do good evaluation, they will avoid the trap of getting lost in the search for explanations at the expense of the primary task, which is the evaluation itself.