Factorial Equations for Tests of Attention

Tests designed to measure what was conceived to be attention were found by factor analysis to involve a factor which is independent of the factors of rote memory, visual-space, number, or perception. To a large extent, at least, this attention factor is independent of content and of mode of presentation of test material. The tests in which the variance is mainly dependent upon this factor are those involving a high degree of sustained or relatively continuous mental effort.