Women entrepreneurs, in particular, may not be able or wish to reveal increases in their income resulting from a project intervention such as training. This article describes an evaluation method evolved to assess the effectiveness of the Grassroot Management Training programmes run by the ILO in three African countries. The method involves assessing changes in attitudes towards relevant learning among the participants of the training seminar, compared with the changes in attitudes of a control group over the same period. Participants are also asked how much they would be prepared to pay for another seminar of a similar type, as a proxy measure of the estimated benefits accrued by the participants. From this a cost-benefit ratio can be derived.