Many years ago when the profession of teaching was not a profession-even as professions went those days-primary qualifications for teachers were knowledge of subject-matter and physical stamina. If one had studied his Greek, Latin, and Grammar, and if he were able to calculate tolerably well he might become a teacher. That was providing, of course, he had the physical strength to browbeat overgrown boys into submission and to meet the rigors of working in essentialy uninhabitable school houses. It is doubtful that anyone views the passing of those times and conditions with regret. Frotunately for teacher, pupil, and nation, such days are gone from most areas of our land. Over the years certain worthwhile principles and procedures related to the preparation of teachers were developed and generally accepted. With improved teacher preparation came status. Teaching was recognized as an art, a science, a profession that demanded special preparation beyond knowledge of subject matter. It was demonstrated over and over again that knowing what to teach did not insure knowing how to teach, any more than a surgeon's knowing what to remove from a patient insured his skill in performing the operation. There were, and are, a lot of things a person should know if he is to teach children well. Not only should he know his facts, he should understand pupil motivation-how to present the subject so the learner became personally involved and, perhaps, even carried on a deep interest the rest of his life. A good teacher should know how to organize his teaching into meaningful units that lend themselves to investigation and study; how to select or construct tests and to administer, tabulate and interpret test results; how to meet the individual differences that exist in such unbelievable range in every group of children.