An Investigation by Ivnik Et Al

An investigation by Ivnik et al.(2000) on the validity of four different approaches to interpreting test data concluded that

A) cutoff scores are essentially worthless.
B) cutoff scores can be used instead of more complex indices like difference scores or patterns of scores.
C) all approaches to interpreting neuropsychological test data are equally valid.
D) the use of cutoff scores is adequate for novices in the field, but experts should rely more heavily upon more complex indices like difference scores or patterns of scores.