peer and self-assessment strategies among their students. Although this list is not complete, it does begin to show the scope of professional development that is required to achieve high-quality classroom assessment. Many teachers already engage smoothly and effectively in the processes associated with effective classroom assessment, but these practices need to be developed and enhanced in all classrooms and among all teachers.

Change in assessment practices that are closely linked to everyday teaching will not come about through occasional in-service days or special workshops. Teacher professional-development research (Loucks-Horsley, Hewson, Love, & Stiles, 1998) indicates that a “one-shot” teacher professional-development experience is not effective in almost any significant attempt to improve teaching practice. Because the kind of assessment discussed in this document is intimately associated with a teacher's fundamental approach to her responsibilities and not simply an add-on to current practice, professional development must permit the examination of basic questions about what it means to be a teacher. Professional development needs to become a continuous process (see Professional Development Standards, NRC, 1996), where teachers have opportunities to engage in professional growth throughout their careers.

As Black's statement at the outset of this chapter suggests, widespread formative assessment will not come about solely through changes in policies nor solely by adopting specific programs. New techniques can help, but understanding the basis for the new techniques also is necessary if it is to be implemented in a manner consistent with its intent. Yet a teacher cannot successfully implement all of the changes overnight. Successful and lasting change takes time and deep examination. It becomes critical to root professional-development experiences in what teachers actually do. This approach also is consistent with what research says about teacher learning. A recent study by the NRC (1999a) asserts that teachers continue to learn about teaching in many ways. Primarily, the study states, “they learn from their own practice” (p. 179). Teachers develop repertoires of action that are shaped both by standards and by the knowledge that is gleaned in practice (Wenger, 1998).

The standards for assessment and teaching stress the importance of