Validity of the Woodcock-Johnson tests of achievement for learning-disabled students

Two independent samples of 40 and 32 elementary-aged, learning-disabled (LD) pupils were administered the Woodcock-Johnson Tests of Achievement (WJTA), the Peabody Individual Achievement Test (PIAT), and the Wide Range Achievement Test (WRAT) following seven instructional months in an LD self-contained class. Concurrent validity coefficients between W-J achievement clusters and corresponding WRAT and PIAT subtests ranged between .64 and .93. Results from both samples were convergent, thus allowing corroboration of findings. Discrepancies among WJTA, WRAT, and PIAT grade equivalents and standard scores are discussed, as are possible limitations of the WJTA for use with learning disabled pupils.