Policy makers constantly face uncertainty, which makes achieving their goals problematic. To overcome this uncertainty, they employ tools to drive down uncertainty and make probabilistic decisions. We provide a method for scholars to assess empirically how actors make probabilistic predictions. We focus on the interactions between the executive and judicial branches, analyzing the conditions under which justices force the United States to provide them with information. Our approach generates substantive knowledge about interbranch behavior as well as a methodological innovation available to scholars who study political decision making under conditions of limited information.