EVALUATION The Mainstreaming Initiative explores how standard evaluation practice reflects and informs scaling activity, since learning and adaptation are critical elements of effective scaling strategies. Evaluation Guidelines of Official International Development FundersAbstract Development funders have an important role to play in supporting the pursuit of sustainable impact by the implementers of development programs, but this requires that they systematically integrate the objective of scaling, i.e., achieving sustainable impact at scale into their mission and their operational practices. Evaluation and evaluation guidelines are potentially important instruments for [...]