CIES 2018 Presentation, given by Matthew Jukes. Randomized controlled trials (RCTs) have been used increasingly in an effort to reduce uncertainty and improve rigour of impact estimates. However, RCTs do not provide certainty in other important aspects of the evaluation, such as its external validity and in understanding which components of a complex program are essential for its effectiveness. This paper reviews two additional approaches which are currently underutilized which may help researchers and policy makers make better use of uncertain evidence.