Artificial intelligence (Intelligence, IQ, and g)

Intelligence, IQ, and g are unusual. Intelligence is the word used in normal discourse to refer to cognitive capability. However, it is generally regarded as too vague to be useful for a scientific treatment of the subject. The intelligence quotient is an index calculated from the scores on test items judged by experts to include the abilities enclosed by the term intelligence. IQ measures a multidimensional quantity: it is an amalgam of different kinds of abilities, the proportions of which may differ between IQ tests. The dimensionality of IQ scores can be studied by factor analysis, which reveals a single dominant factor underlying the scores on all IQ tests. This factor, which is a hypothetical construct, is called g. Variation in g corresponds closely to the innate notion of intelligence, and thus g is sometimes called general cognitive ability or common intelligence.