ABSTRACT
Among such great pioneers of psychology as Freud, Pavlov, Thorndike, and Watson, two are great because they learned how to measure something that could not be measured before. As mentioned earlier, Hermann Ebbinghaus invented nonsense syllables and then measured memory by counting the number of syllables a subject could remember some time after having learned a list of them. Alfred Binet, with whom we are now concerned, invented a set of simple questions and problems to put to children and, by counting the number of satisfactory answers and comparing them with those of other children, both defined and measured a child’s intelligence. The questions and problems were simple indeed, related to common everyday experience, and it was a stroke of genius to realize how revealing they could be of a child’s mental development. Binet made the great discovery, and all later work on intelligence is really a development of his original idea. Test items (the individual questions or problems) have been extended and improved, tests suitable for older persons and for measuring different aspects or kinds of intelligence 1 have been developed, but it was Binet who showed in principle how all this could be done.
