The Council of Chief State School Officers (CCSSO), through the Interstate School Leaders Licensure Consortium (ISLLC), developed standards for the knowledge, skills, and dispositions necessary for effective practice by educational leaders (CCSSO, 1996). These standards provide a viable content domain from which to assess leader cognitive and affective learning. The Educational Leader Candidate Belief Scale (ELCBS) is used for measuring educational candidates' leadership dispositions. ELCBS was built based on a systematic sampling process of the ISLLC performance expectations dispositions. Initial evidence of validity and reliability are presented, using the Rasch model of item response theory. The interval-level scale being produced, along with additional measures being developed, provides the potential to assess leaders' impact on children's achievement. (Contains 1 figure, 3 tables and 4 footnotes.)