While the initial phases of instructional program development are heavily dependent on knowledge sources outside the classroom, knowledge developed in the classroom by the individual teacher is usually vital to program implementation. Interviews with teachers, principals, and district administrators connected with four urban elementary schools where new programs of reading instruction were being implemented revealed that the organizational characteristics of the schools were closely related to the kinds of knowledge sources used in both program development and program implementation. In contrast to programs in schools where decisions were made at the building level, district-mandated programs tended to be more procedural and practical in orientation than ideological or theoretical; this apparently influenced both teachers and principals to place little emphasis on knowledge of their students' needs and characteristics when implementing the programs. The authors suggest that if information about students is an indispensable ingredient of productive teaching, the growing trend toward selection and control of programs at a great administrative distance from the classroom may be counterproductive. (Author/PGD)