In the past, evaluation of teacher performance often focused on generic behaviors related to common instructional strategies (Medley, Coker, & Soar, 1984). More recently, educational researchers and test developers have focused more on teachers' subject matter knowledge as tested through tools like the Praxis and California's Single Subject Assessment Tests. Most states now test basic skills and subject matter knowledge (Madaus & Mehrens, 1990). However, useful assessments of teachers' knowledge of development, learning, and pedagogical strategies have been more difficult to develop. To address this gap, the Interstate New Teacher Assessment and Support Consortium (INTASC, 1992), in conjunction with the Educational Testing Service [ETS], developed a prototype for a Test for Teaching Knowledge [TTK]. The TTK is designed to evaluate the foundational teaching knowledge of learning, learners, and development described by Darling-Hammond, Wise, and Klein (1999) and is intended to be used as a measure of candidates' teaching readiness. This study focuses on the Stanford Teacher Education Program's (STEP) use of the INTASC Test of Teaching Knowledge to gauge changes in preservice candidates' areas of knowledge and skills over the twelve-month program. This paper describes the test, reports changes in the pre-service candidates' performance on the assessment, and discusses implications of the findings for the STEP program and other teacher education programs. (Contains 3 tables and 1 note.)