Score Classification Quick Reference

Score Type Classification Bands

Classification	Standard Score (M=100, SD=15)	Scaled Score (M=10, SD=3)	T-Score (M=50, SD=10)	Percentile Rank	z-Score	Stanine
Very Superior	≥ 130	≥ 17	≥ 70	≥ 98th	≥ +2.00	9
Superior	120 – 129	15 – 16	63 – 69	91st – 97th	+1.33 to +1.99	8
High Average	110 – 119	13 – 14	57 – 62	75th – 90th	+0.67 to +1.32	7
Average	90 – 109	8 – 12	43 – 56	25th – 74th	−0.67 to +0.66	4 – 6
Low Average	80 – 89	6 – 7	37 – 42	9th – 24th	−1.33 to −0.68	3
Below Average	70 – 79	4 – 5	30 – 36	2nd – 8th	−2.00 to −1.34	2
Extremely Low	≤ 69	≤ 3	≤ 29	≤ 1st	≤ −2.01	1

Score Type Reference

Standard Scores (SS)

Used by WJ-V, WIAT-IV, KTEA-3, CTOPP-2, TAPS-4, Vineland-3, ABAS-3. M=100, SD=15. Most common composite score type in FIE reporting.

Scaled Scores

Used for subtest scores on WISC-V, KABC-II, WIAT-IV subtests, CTOPP-2 subtests. M=10, SD=3. Convert to SS for composite comparisons.

T-Scores

Used by Conners-4, BASC-3, BRIEF-2, SRS-2, DP-4, ASRS. M=50, SD=10. Higher = more concern on behavior rating scales.

Percentile Ranks (PR)

Percent of same-age peers scoring at or below that score. PR 50 = average. Non-linear — distance between ranks is not equal. Do not average PRs.

z-Scores

M=0, SD=1. Primarily used in PSW/XBA discrepancy analysis and cross-battery comparisons. Positive = above average; negative = below average.

Stanines

Whole-number scale 1–9. Used in some older batteries and state assessments. Stanine 5 = average. Broad-band — each stanine spans ≈ 0.5 SD.

CHC Broad Abilities — Quick Reference

Code	Ability	What It Measures	Common Batteries	SLD Relevance
Gc	Crystallized Intelligence	Acquired knowledge, vocabulary, verbal reasoning, language development	WJ-V (Oral Language), WISC-V (VCI), KABC-II (Knowledge)	Oral Expression, Listening Comprehension; language difference vs. disorder
Gf	Fluid Reasoning	Novel problem solving, inductive/deductive reasoning, pattern recognition	WJ-V (Fluid Reasoning), WISC-V (FRI), KABC-II (Planning)	Math Problem Solving; SLD-MPS, PSW processing deficit indicator
Gwm	Working Memory	Holding and manipulating information in short-term storage	WJ-V (Working Memory), WISC-V (WMI), CTOPP-2 (Phonological Memory)	Reading Fluency, Written Expression; key SLD processing deficit
Gs	Processing Speed	Speed and efficiency of simple cognitive tasks	WJ-V (Processing Speed), WISC-V (PSI)	Reading/Math Fluency; SLD-RF indicator; ADHD-related efficiency concerns
Ga	Auditory Processing	Discrimination, analysis, synthesis of auditory/phonological information	CTOPP-2, WJ-V (Auditory Processing), TAPS-4	Basic Reading, Reading Fluency; core dyslexia indicator; SLD-BR/RF
Grw	Reading/Writing	Reading decoding, fluency, comprehension; written expression	WJ-V (ACH Reading/Written Lang), WIAT-IV, KTEA-3	All reading and writing SLD domains; achievement side of XBA/PSW
Glr	Long-Term Retrieval	Storing and fluently retrieving information from long-term memory	WJ-V (Long-Term Retrieval), CTOPP-2 (Rapid Naming)	Reading Fluency; RAN deficits; naming speed indicator for dyslexia
Gv	Visual-Spatial Processing	Perceiving, analyzing, and mentally manipulating visual information	WJ-V (Visual-Spatial Thinking), WISC-V (VSI), KABC-II (Simultaneous)	Less central to SLD; relevant for dyscalculia, graphomotor dysgraphia
Gq	Quantitative Knowledge	Math achievement — calculation and applied problem solving	WJ-V (Math), WIAT-IV (Math), KTEA-3 (Math)	SLD-MC and SLD-MPS; dyscalculia; achievement side of math XBA

Note: Classification band labels vary by publisher. Some batteries (e.g., WJ-V) use "Low" instead of "Below Average" and "Very Low" instead of "Extremely Low." Always defer to the test publisher's descriptor table when reporting. This reference uses the most common Texas diagnostician convention. Percentile ranges reflect standard normal distribution approximations and may differ slightly by battery. For behavior rating scales (Conners-4, BASC-3, BRIEF-2), elevated T-scores (≥60–65) indicate concern — interpret direction per publisher guidance. z-score ranges are mathematically derived and exact. This document does not constitute a norming table for any specific assessment instrument.

SCORE CLASSIFICATION QUICK REFERENCE