We systematically assessed the relationships between growth of four components of verbal ability--Information, Similarities, Vocabulary, and Comprehension subtests of the Wechsler Intelligence Scale-Revised--and longitudinal growth from Grades 1 to 9 of the Woodcock-Johnson Psycho-Educational Battery Passage Comprehension subtest while controlling…

The purpose of the present studies was to test the hypothesis that the psychometric characteristics of ability scales may be significantly distorted if one accounts for emotional factors during test taking. Specifically, the present studies evaluate the effects of anxiety and motivation on the item difficulties of the Rasch model. In Study 1, the…