The Continuum of Teacher Development describes teaching practice and professional development throughout a teacher's career. For nearly two decades, the Continuum has been implemented successfully as part of ongoing collaborations between beginning teachers and their mentors or coaches to assess practice and set goals for professional development over time.

The Continuum is aligned with six professional teaching standards (each containing specific elements of teaching practice) and is organized to describe five developmental levels of performance: Beginning, Emerging, Applying, Integrating and Innovating. The levels do not represent a chronological sequence in a teacher's growth, but rather developmental levels of performance. One might expect a beginning teacher to assess at “Beginning” level and it would not be viewed as a deficit position. And, a teacher may be at a beginning or emerging level of practice in some places on the Continuum and at advanced levels in some others, no matter how many years she or he has been in the profession.

The Continuum is meant as a guide for self-reflection, self-assessment and conversation among beginning teachers, mentors and site administrators, helping teachers to interpret their teaching and make informed decisions about their ongoing development as professionals. It is not a rubric to define performance standards or expectations, nor is it an isolated observation instrument. In the New Teacher Center 's Formative Assessment System (FAS) the Continuum serves as the entry point for developing an Individual Learning Plan in which teachers identify and work towards professional goals. It has proven to be a powerful tool as teachers identify their areas of growth, move from assistance to autonomy and become lifelong learners.

An accompanying guidebook, Using the Continuum of Teacher Development, provides mentors with information on how to use the Continuum to support teacher growth.