The most influential proponent of this approach was jean piaget: information processing approach an approach to the study of intelligence that focuses on the types of skills people use to think and to solve problems. N the differential approach assumes that we can best investigate the nature of intelligence by studying the ways in which people differ on tests of such intellectual abilities. N psychologists have devised intelligence tests that yield a single number, usually called an iq score: but the fact that intelligence is a single, general characteristic. N some researchers promote the idea that some intellectual abilities are completely independent of one another: e. g. a person can be excellent at spatial reasoning but poor at solving verbal analogies. S comprises of three qualitative principles of cognition : N apprehension of experience, eduction of relations, and eduction of correlates.