Synopsis One of the most important sources of curriculum and curricular change has been the knowledge explosion. Since it is manifestly impossible to teach everything there is to know, educators must select from among a growing number of options that which is most appropriate and important for a child to know. With the expansion of knowledge, the ability of students to think for themselves and act like scientists became important curricular objectives, in addition to the traditional mastery of information. Modern technology in the form of computers, machinery of all types, and the mass media have also had profound curricular implications, not only from the standpoint of the kinds of jobs for which the schools must prepare their students, but also in the way in which technology can be put to instructional use. Numerous other societal influences, such as the environmental crises issues of war and peace, life expectancy and other demographic factors, and economic factors of wealth and poverty, affect what happens to the child in the school setting.