Woodcock-Johnson IV Standard Score and Relative Proficiency Index (RPI) Interpretation Charts

Woodcock-Johnson IV (WJ IV) emphasizes the identification of strengths and weaknesses by providing comparisons within and across each of its three co-normed batteries. This complete assessment system offers the ease of use and flexibility examiners need to evaluate learning problems and improve instructional outcomes for children and adults in a way that no other assessment can.

Standard Score and Percentile Rank Classification

In writing reports or communicating test results to parents and others, examiners may prefer to use verbal labels rather than numbers to describe test performance. The table below provides a classification of Standard Score and Percentile Rank ranges as a guideline for describing an individual's relative standing among age or grade peers. This classification applies to the WJ IV Tests of Achievement, Tests of Cognitive Abilities, and Tests of Oral Language.

Relative Proficiency Index (RPI) and CALP Levels

In addition to norm-referenced scores such as Standard Scores and Percentile Ranks, WJ IV provides Relative Proficiency Index (RPI) scores, which describe an examinee's proficiency with age-level tasks. For the Oral Language battery, RPI scores can also be reported as Cognitive-Academic Language Proficiency (CALP) levels — a six-level classification (with two additional in-between "regions of uncertainty") that describes English or Spanish language proficiency specifically. This classification applies to the Oral Language, Broad Oral Language, Listening Comprehension, and Oral Expression clusters, as well as the corresponding Spanish-language clusters.