 NWP sites share a national program model, adhering to a set of shared principles and practices for teachers' professional development, and offering programs that are common across the network.In addition to developing a leadership cadre of local teachers (called "teacher-consultants") through invitational summer institutes, NWP sites design and deliver customized inservice programs for local schools, districts, and higher education institutions, and they provide a diverse array of continuing education and research opportunities for teachers at all levels.National research studies have confirmed significant gains in writing performance among students of teachers who have participated in NWP programs.