Microenterprise programs attempt to help poor people start or strengthen small businesses. Funding and political support has grown rapidly. Is microenterprise a good use of scarce development funds? Unfortunately, most evaluations have been case studies in what not to do. Because benefits and costs cannot be measured completely nor with perfect certainty, rigorous evaluations should support their necessarily subjective judgements with logic and explicit assumptions. The usefulness of an evaluation lies not in its (apparent) incontrovertibility but rather in its clarity of assumptions and in its openness to meaningful review and critique.