On the nature of intelligence.

Our concept of intelligence has been heavily influenced by the development of intelligence tests as screening devices in education and personnel selection. An alternative approach is to begin with a theory of the process of cognition and identify those aspects of individual mental performance that should be important on theoretical grounds. Three classes of performance have been identified. These deal with a person's choice of an internal representation for a problem, strategies for manipulating the representation, and abilities to execute elementary information processing steps required by the strategy.