Calls for rigorous impact evaluation has been accompanied by the quest for what works and why. Howard White identifies six principles for the successful application of the approach — mapping out the causal chain (programme theory), understanding the context, anticipating heterogeneity, rigorous evaluation of impact using a credible counterfactual, rigorous factual analysis and using mixed methods.
Phi Beta Iota: The international Initiative for Impact Evaluation, which receives support from the Bill and Melinda Gates Foundation, is doing important work, but in isolation from a larger canvas. They lack a strategic analytic model for studying the whole. This is typical of all intelligence and information analytic endeavors, all mired in 20th Century stove-pipe thinking.