Test prep on the Praxis Principles of Learning and Teaching teacher certification tests (5621, 5622, 5623, 5624), including a model full-length practice test for each. The Praxis Principles of Learning and Teaching (PLT) tests assess a new teacher's knowledge and understanding of educational practices foundational to beginning a career as a professional educator. The tests' content focuses on key indicators of an educator's knowledge of topics such as human development, learning processes, instructional processes, diverse learners, and professional issues. AUTHOR: Diane E. Kern, Ph.D., is Assistant Professor of Education at the University of Rhode Island and a member of the School of Education's ad hoc committee on licensure tests. She resides in Wakefield, Rhode Island.