"Since impact evaluations focus on results and what contributes to results, logically there should be a greater enthusiasm for making use of the findings. Impact evaluations also tend to cost more than other types of evaluation, implying that they should command significant follow up as well. It turns out, however, that credible evidence and significant costs are not sufficient to ensure that impact evaluation findings are used. This guidance note looks to several additional factors that contribute to effective evaluation use. Using impact evaluations depends importantly on how one designs and conducts them. As was illustrated in Guidance Note 3 on mixed methods, the choice of evaluation method should follow from the questions one is trying to answer. But whatever questions are being tackled, whatever evaluation methods are employed, to make the best and proper use of evaluation findings we can apply a common set of practices and insights." (Introduction)