Absence of parallel forms for the traditional individual intelligence tests

The issue of the absence of parallel forms for the traditional individual intelligence tests has received little attention in the area of psychological testing ever since the early demise of the Wechsler Bellevue Form II and the delayed discontinuance of Form M of the Stanford-Binet Intelligence Scale. Five reasons have been presented here to argue that the availability of parallel forms could have both theoretical and practical benefits, especially if the constructors of individual ability and/or achievement tests employ the recent advances in item response theory and computer technology.