INTRODUCTION There are few theories of learning that have had as marked an effect upon US educational practice as Thorndike's. Much of this was due to his prodigious volume ofwriting. An unusually creative scholar, he was author or co-author of more than 500 books and articles. His influence on psychological and educational thinking has been worldwide. Much ofhis time and attention was devoted to theoretical aspects of learning, but even more to the applied aspects and classroom situations. The specificity of Thorndike's theory contributed much to its applicability.