IQ Final Scores and Score Interpretation

Verbal Comprehension Index (VCI)

The WAIS/WISC index score most influenced by bias related to race and educational opportunity.

Raw Score

The unadjusted number of items correct or points earned on a test.

Standard Score

A statistically transformed version of a raw score, expressed on a scale with a known mean and standard deviation.

T Score

A standardized score with a mean of 50 and a standard deviation of 10.

Composite Score

The score used for indices and Full Scale IQ (FSIQ) on the WAIS-IV and WISC-V.

Scale Score

The score used for subtests on the WAIS-IV and WISC-V.

Subtest Mean and Standard Deviation

The mean for subtest scores is 10 with a standard deviation of 3.

Index Score Mean and Standard Deviation

The mean for index scores is 100 with a standard deviation of 15.

Very Superior

Qualitative label for index-level standard scores of 130 and above.

Average

Qualitative label for index-level standard scores of 90 - 109.

Percentile

Indicates how an individual’s score compares to same-age peers in the normative sample.

Confidence Interval (CI)

A range of scores expressing the uncertainty around a person’s obtained test score.

Age Equivalent

The age level at which the average child earns the same raw score as the examinee.

Statistically Different

A term indicating that a score varies enough to warrant clinical attention.

Basal

The point on a test indicating the level of functioning at which the evaluator is certain all prior items would be answered correctly.

Ceiling

The test point at which the client has made a predetermined number of errors, stopping further administration.

Start Point

The designated starting position in a test based on the client’s age, to determine if the basal has been met.

Test Validity Issues

Factors such as fatigue, illness, or test anxiety that can invalidate test results.