Weschler's IQ Test Score Interpretation
By Inderbir Kaur Sandhu, Ph.D
My son who is 11 now underwent a Wechsler IQ test few months ago. His
overall score is 143. Below is the break-up of scores:
Vocabulary Raw score is 58, T score is 73
Block design Raw score 60, T score 75
Similarities raw score 38, T score is 74
Metric reasoning raw score is 28, T score is 61
Sums of T score 147, performance 136, 4 sub tests 283
Verbal Sum of T Score 147, IQ 143 percentile 99.8% Performance Sum of T
score 136, IQ is 133 percentile 99% Total 4 sub test sum of T scores
283, IQ 143.
How do I interpret this? What does it mean? Please explain. Thank you.
Based on the overall score of 143, your son is in the highest range with
superior score. This appears to be The WASI II, a revision of the WASI,
which provides a brief, reliable measure of cognitive ability. The WASI
II can be used in conjunction with the comprehensive Wechsler scales as
a screening instrument to determine if in-depth intellectual assessment
is necessary, or as a re-evaluation tool to follow up on comprehensive
testing. If the WASI-II is used as a re-evaluation tool, it provides
comparable FSIQ, VCI, and PRI scores to ensure interpretation of change
over time is clear and meaningful.
Standard scores transform individual raw scores into a standard form
that provides a more meaningful description of the individual scores
within the distribution. T-scores are standard scores with a mean
(average) of 50 and a standard deviation of 10. If the variable measured
by a psychological test is normally distributed, we would expect that
two-thirds (68.26%) of the population would obtain scores between 40 and
60. This is considered the normal range. You son obtained T scores in
the range of 61 to 75, which is above average. Further, it would be
expected that 95% of the distribution lies within 2 standard deviations
of the mean (that is T-scores between 30 and 70). Thus, scores that fall
above 70 or below 30 would be considered unusually high and unusually
low, as only 5% of the population obtains higher or lower scores.
Apart from Matric Reasoning, your son scores are considered very high
for the other three subsets. Your son should qualify for the gifted
education programme. Speak to the school authorities to help with your
son's ability-educational match.
All the best!