The use of constructivism and its various manifestations in education has been a topic of much interest in recent years. Inquiry into this theoretical framework has resulted in teacher educators' attempts to help their teacher candidates apply constructivist pedagogy in university classrooms, field experiences and student teaching at two US universities. The instructors developed a set of co-requisite, interdisciplinary methods courses entitled the Schoolyard Lab Program. Composed of two three-credit courses (science methods and language arts methods) and a one-credit field experience, the Schoolyard Lab program utilized the "Cognitive Process of Instruction (CPOI)" as its pedagogical basis. Joan Fulton designed CPOI as a seven-step process that relies on the learner's ability to describe a concept based on its distinguishing attributes, investigate and compare examples of the concept and, finally, apply the concept in new and authentic contexts. The Schoolyard Lab Program is the result of a 6 year period of development and has shown significant positive effects of CPOI on the self-efficacy beliefs of teacher candidates and in-service teachers who have experienced the program. The two faculty modeled CPOI practices in the university classroom. Teacher candidates were then expected to develop an integrated science and language arts unit plan, applying these same principles in elementary classrooms as they completed field experiences and student teaching. The authors of this article explain the CPOI format, how it conforms to important parts of the teacher education curriculum (such as lesson and unit development) and how this relates to the overall objectives of concept development, subject interrelationships and assessment strategies. (Contains 2 figures.)