Rutherford and Ahlgren (1990) discuss the time element involved in an educational reform:
Professions may change mostly in response to turnover. Young physicians and engineers, for instance, carry new knowledge, techniques, and attitudes into those professions. Successive generations of teachers and school administrators can serve in the same way, but only if they come bearing different attitudes, knowledge, and skills than the ones they replace. Reforming teachers' education, therefore, is the sine qua non of school reform, but it will necessarily be slow to make its impact felt.
Monolithic approaches to educational reform are not the American way, and with good reason: No group or sector is in sole possession of wisdom, inventiveness, resources, and authority, and few educational problems of consequence have only one possible solution. But diversity of effort can lead to little impact on a national scale if those who are striving to change things are all heading in different directions without regard for each other. Lockstep in education is neither possible nor desirable, but a commitment to collaboration is. Operationally, such a commitment means sharing ideas and information with others who are addressing the same or related problems. In the context of the reform of science education, this observation applies to the scientific community itself to the degree it wishes to make significant contributions to the process of reform in education." (p. 197-198)