This book is about the practice of decision making by school principals and about ways to improve this practice by capitalizing on evaluation dimensions. Much has been written on decision making but surprisingly little on decision making in the school principalship. Much has been also written on evaluation as well as on evaluation and decision making, but not much has been written on evaluation in decision making, especially decision making in the principalship. This book presents two messages. One is that decision making in the principalship can be studied and improved and not only talked about in abstract terms. The other message is that evaluation can contribute to the understanding of decision making in the principalship and to the improvement of its practice. In this book we call for the conception of an evaluation-minded principal, a principal who has a wide perspective on the nature of evaluation and its potential benefits, a principal who is also inclined to use evaluation perceptions and techniques as part of his/her decision-making process. This book was conceived in 1985 with the idea to combine thoughts about educational administration with thoughts about educational evaluation. Studies of decision making in the principalship had already been on their way. We decided to await the findings, and in the meantime we wrote a first conceptual version of evaluation in decision making. As the studies were completed we wrote a first empirical version of same.