This book is designed to serve as a guide for laboratory experiments in educational psychology. Only those experiments have been selected which have a more or less direct bearing upon educational problems. It is intended to be a laboratory manual for experimental work done parallel with an introductory course in educational psychology, or in other introductory educational courses in which the psychological aspect is emphasized. No previous training in experimental work is necessary. The directions are so given that in most experiments relatively simple apparatus is used. For many experiments the material is contained in the book, for others it may easily be constructed, and for the rest it must be obtained from the sources indicated in each case. In pursuing the laboratory work the order of the chapters permits of considerable flexibility. All chapters except V and VI are independent of one another and any desired order may be adopted. The work is intended to occupy two hours weekly through one semester. It is best to divide the class into groups of not more than eight or ten, in charge of an instructor who shall see that the experiments are done accurately and the notes written up carefully.