One of the most visible changes in philanthropy in the last twenty years has been the increased attention paid by foundations to the results of the activities they support. In The Role of Evaluation in the 21st Century Foundation, Edward Pauly, the principle author, presents the effective use of evaluation by foundations that seek to increase their focus on results, and the benefits and challenges of using evaluation effectively. Given that differing forms of evaluation produce different kinds of learning, the author suggests that foundations can avoid the problems that have limited the usefulness of evaluations by determining what they most need to learn; emphasizing the needs of the users of the evaluation; and closely aligning each evaluation with the purposes and goals of the foundation.