The factor-analytic history of the isolation and identification of the cognitive ability construct known as Number or Numerical Facility is described. Empirical documentation from the psychometric literature is discussed, and examples of items from a variety of tests which have defined and been associated with the Number factor are included to…

The factor-analytic history of the isolation and identification of the mental ability construct known as verbal comprehension is traced through the psychometric literature. Examples of the most important item types which have been found to measure this factor--defined as the ability to understand the English language--are discussed. It has been…

The complex and multi-faceted nature of the cognitive process of reasoning is discussed. The factor-analytic history of the isolation and definition of the three most important currently recognized reasoning factors (general reasoning, induction, and logical or deductive reasoning) is traced through the psychometric literature, and the…

The complex nature of the psychological construct called judgment, the history of its identification as a mental ability, its measurement, and its relationship to other mental abilities are discussed. Factor analytic research which isolated the judgment factor is reviewed. The pervasiveness of the judgment factor throughout a number of diverse…