Teacher educators and teachers must be leaders in developing learner-centered standards for preparing teachers. Standards can help teachers build their own knowledge and understanding of what helps students learn. As schools undergo restructuring, teachers will be responsible for students, not just subject-matter information; for understanding how learning is occurring; and for having tools to assess how students learn and think as well as what they know. Teachers will also be responsible for curriculum development, assessment, decision making about special needs of students, and reaching out to parents from different communities. Licensing requirements and teacher evaluation requirements generally do not focus on this conception of teaching. The National Board for Professional Teaching Standards is setting standards that reflect the real complexities and real judgments that teachers must deal with. Teachers' development of materials to be submitted for Board certification and teachers' reflection upon their teaching are powerful professional development activities. The goal should be to create, use, reflect upon, operationalize, and enliven standards in a way that produces learning. This kind of work among teachers can lead to the development of a profession that can take ownership and leadership for creating and using an expanding base of knowledge to serve all children well. (JDD)