During the twentieth century, scientists and educators have been concerned that school science reflects the actual practice of science, with respect both to content that students learn and to the actual way scientists work. "What is worth learning?" and "How should students learn science?" have been enduring questions. Historically, these concerns have been expressed in the National Society for the Study of Education (NSSE) Yearbooks and elsewhere. The Forty-sixth Yearbook Committee expressed its opinion on how science should be taught.Since experimenting involves "learning by doing," there can be no substitute for it. Pupil experimentation is an essential part of good science education. In every course of science offered at any level, therefore, opportunities should be provided for the pupils to perform experiments. 2 205