Synopsis This book proposes ways of building competence in the teacher of science. It is concerned with the use of the laboratory--interpreted broadly--as the basis for experience. The contents have been planned primarily for teachers of general and physical science in the secondary school. Much of the entire book should be valuable to teachers concerned with chemistry in the schools and colleges. This book has two purpose. One is to make the new teaching methods developed from these concepts and models more useful to teachers already somewhat familiar with them. The other is to inform other teachers of the possibilities for improved student understanding that these methods offer.