Should aid evaluation focus on accountability for results or learning? In the January 2018 edition of Evaluation, Lauren Kogen rejected the conflation of these distinct roles and the resulting marginalization of learning in aid evaluation. She viewed the growing dominance of the accountability criterion as a defensive reaction to aid skepticism and observed that focusing on the does it work' question has led to neglecting the most important evaluative questions ("why and how does aid work - when it does'). Hence, she advocated restoring learning to a privileged place in aid evaluation and called for greater emphasis on participatory development and social learning. This review article endorses Kogen's overall diagnostic but points to the growing scholarly consensus about aid effectiveness; stresses the complementarity between accountability and learning in aid evaluation; and argues that a proper use of generally agreed development evaluation criteria would decisively address the legitimate concerns raised in Kogen's spirited contribution.