Gifted Issues Discussion homepage Forums Parenting and Advocacy understanding subtests

To the very knowledgeable posters here- I would greatly appreciate more detailed clarification on the subtests scores and how they relate to the VIQ, PIQ, and FSIQ scores.

I see many posters who mention actual subtest scores, and lots of discussion on getting 19's, 18's and 17's. Please explain to me how those "scaled" scores turn into the numbers 130-160. Somehow I must have missed this in the past posts. If someone knows specifically for WPPSI, that would be even better.
Thanks in advance for your help.

Thanks Dottie,
You are always so full of good info.
I do have some questions.
First - if 10=100, 13= 115, 16=130 19=145 - Then how does the test ceiling at 160? Isn't 19 the highest you could get in every subset? And if 19 is the highest and does correlate to 145, than how does DYS need a 150, wouldn't that be impossible?


Since my post I have been doing internet research. WPPSI for the 4-7 year old age group has 7 core subtests. 3 that correlate to VIQ, 3 that correlate to PIQ and 1 that correlates to Processing Speed. It also says that for the VIQ, PIQ and FSIQ you only calculate using the core subtests.

So, after you tally the the subtests for VIQ and PIQ, is it an average that is read from a chart for the FIQ and PIQ scales? I did read somewhere, but not sure how reliable it is, that it is just a straight average. If you have three subtests for VIQ, say two 18's and a 19, then you take the average of the three, and you get 18.3, then your VIQ score is whatever 18.3 would correlate to. I guess that is what the chart you refer to does?
If 19 is 145, and 16 is 130, then an 18.3 would be something around a 142??

If our tester used the core and optional subtests to calculate the IQ scores, (she was not gifted experienced and said she did everything by hand), wouldn't those scores be incorrect and wouldn't they need to be redone without the optional subtests included?

Another reader's post, mentioning ceilings and noting their child's scores on the WPPSI got me pulling out our test which was taken about 9 months ago. I just want to make sure that I understand the process and that the scoring was done correctly.
Thanks

This is a great post as Ive had similar questions about the subtests. With the help of all of you very knowledgeable ladies I may actually start to understand all of this!

Just curious: dd's processing speed was her weakest area on the WISC IV. What exactly is that?

Thanks Dottie - I would love to take you up on your offer and share with you via PM. I just have to figure out how to do that.

For Tammiane - Here is something I found on this Davidson site re: processing speed.
Tips for Parents: Intellectual Assessment of Exceptionally and Profoundly Gifted Children

Author(s): John D. Wasserman
Source: Davidson Institute for Talent Development/Young Scholar Seminar 2006
Some tests measure abilities that can easily (and spuriously) depress your child�s overall IQ score. For example, performance speed (summarized in the Processing Speed Index) contributes 20% to WISC-IV Full Scale IQ, and our data suggests that over 70% of students applying for gifted placement have Processing Speed Index scores in the average range or below

Thanks, both of you! That really helps me understand a bit more. Its very interesting that over 70% who applied for GT had processing speed scores similar to dd.

Its crazy to see 19's and 17's on over half the sub tests but then see a 9 on block design (!!) and 10 on coding. Those were her two weak areas. Funny that the day after the test she had literally mastered block design! I wonder what she'd get on that subtest now and how much that would change her overall score? Its all a "what if" now but I can't help but wonder!