Making Sense of WPPSI-IV and SBIS-5 Intelligence Scores
By Inderbir Kaur Sandhu, Ph.D
Q: My son and daughter were both tested by license Ph.D last year (2016) with the WPPSI-IV and SBIS-5 - both tested well but I cannot figure out how to read/understand/make use of their scores. My daughter also had significant discrepancy between her SBIS-5 scores and her WPPSI scores - I test the same way and was diagnosed dyslexic/gifted at age 8. I had my kids tested early on because I know it can be genetic - my son's scores are exact, but daughter is off, scoring much lower on WPPSI. I have heard that WPPSI is bias toward dyslexics, which makes sense as I have consistently tested at 136 on SB and 117-125 on the WEIS.
They are already in the gifted program - not worried about that - just trying to make sense out of deeper meanings.
My daughter (nearly 4 at testing WPPSI-IV):
Indices of WPPSI-IV: Raw Standard Score Percentile
Full Scale Index -- 118 88
Verbal Comprehension Index -- 117 87
Visual Spatial Index -- 109 73
Working Memory -- 121 92
Subtests: Raw Score Percentile
Receptive Vocabulary 18 13 84
Block Design 14 10 50
Picture Memory 14 14 91
Information 18 13 84
Object Assembly 18 13 84
(Zoo Locations) 10 13 84
(Picture Naming) 18 13 84
Stanford Binet Intelligence Scales - 5th Edition Index Scores:
Quantitative Reasoning Score - 127 / Percentile - 96
Subtest Scores:
Nonverbal Quantitative Reasoning Scaled Score - 17 Percentile - 99 Verbal Quantitative Reasoning Scaled Score - 13 Percentile - 84
I am looking for help find written discussion/explanation of what the Index Score means, how the Subtest Scores are combine to produce the Index.
Also would like to understand if discrepancy is normal for a very young child or is an indication of learning disability.
Already I find myself struggling with my daughter (now 5) on reading/writing when my son was a breeze. I cannot decide if she is lazy (I HATED being accused on this when I was young) or needs a alternative learning style. I don't know how to help her learn in a different way, I have no idea how I eventually learned to read/write - but obvious I did.
Any help with these two questions - source for understanding Index/Scales and Testing Discrepancies would be greatly appreciated.
A: Based on your experiences, it is best to not assume that your daughter is lazy. It is possible that she learns differently. Or what she is learning is not challenging and meaningful enough to get her stimulated. Or she probably has learning concerns and this needs to be determined to rule out or get early intervention. Whatever the case is, it required a lot more than just the scores of IQ tests.
The Stanford Binet 5 (SB5) now has five factors, (Fluid Reasoning, Knowledge, Quantitative Reasoning, Visual-Spatial Processing, and Working Memory) which translate to verbal and performance scores. Raw scores are converted into scaled scores using age appropriate tables. It is not converted directly – and the table is one that has been prepared based on the norms of research done The scaled scores are summed for Nonverbal, Verbal and Full Scale IQ as well as for the five factor index scores. These are all normalized standard scores (Mean=100, Standard Deviation=15). Percentile rank equivalent are also obtained. Some reading on SB5 here:
http://www.proedinc.com/Downloads/14462 SB-5_OSRS_SampleDescriptiveReport.pdf
Math tends to be correlated with nonverbal reasoning while reading/writing is more connected with verbal reasoning. Therefore strengths and weaknesses on these aspects could indicate a pattern. On the WPSSI, she clearly indicated a significant weakness on Block Design (Visual Spatial Reasoning), which brought down her scores and should be looked into.
The discrepancies between the tests are hard to compare, as they are two different tests. The testing of these two instruments is not necessarily interchangeable and highlights the potential dangers of relying on one result, obtained from one measure, on a single occasion. It is best to speak to the psychologist to figure out reason/s for the discrepancies within the same test (the subsets) and between tests since both these tests correlate well. Best wishes!
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