This is a work on "hostile" data and the conditions under which they are accepted and rejected. What is the place of data in politics and organization? Why are politicians and administrators so often hostile to research data, or why do they tend to perceive data as hostile to them? How can data become relevant to policy? These questions are the focus of this book. In answer I try to show how political and administrative institutions cope with "hostile" data; how they seek to maintain closedness to disconfirming data, and how they are led, in a free society, to change their policies despite...