Showing posts with label BAT III. Show all posts
Showing posts with label BAT III. Show all posts

Wednesday, April 21, 2010

IQ Test DNA Fingerprints: Comparison of WJ III/BAT III to WJ-R/BAT-R

Here is another of IQ's Corner "IQ Test CHC DNA Fingerprint" test comparison series.  This particular CHC fingerprint figure compares the CHC composition of the respective full scale total composite IQ scores from the WJ III/BAT III and the the earlier version of these batteries....the WJ-R/BAT-R.

Background information regarding the development, use and interpretation of this IQ global IQ score feature can be found at a prior post and in the IQ Test CHC DNA Fingerprint section on the blog side bar.  More can be found at IQ's Corner sister blog...the ICDP blog.

I now present a comparison of the R/III versions of the WJ/BAT batteries as I have seen psych reports where a subject had previously been administered the WJ-R and was later tested with the revised WJ III (in the case of Spanish-speaking individuals, I've seen the BAT-R and the BAT-III---click here for more background information on the Spanish version of the WJ III...the BAT III).  

In the case of the WJ-R/BAT-R, the full scale IQ composite is called the Broad Cognitive Ability (BCA) cluster.  The name was changed in the WJ III/BAT III to General Intellectual Ability (GIA) cluster.  The name change was not cosmetic.  The use of the term "general intellectual ability" in the newest WJ III/BAT III reflects the fact that this global IQ composite score is designed to be the best statistical estimate of the theoretical construct of general intelligence (g) via the use of differential test weights.

Using principal components analysis, a g-factor was extracted from the seven WJ III/BAT III Standard Cognitive battery tests (at each age level), g-factor weights calculated (by age---they shift slightly as a function of age), and the g-weights used to differentially weight the contribution of the seven tests to the composite GIA-Standard cluster score.  The same process was completed for the 14 test GIA-Extended cluster score.  This procedure is explained in detail in the WJ III/BAT III technical manuals/reports and is also briefly summarized in a free on-line Assessment Service Bulletin technical abstract.

In the case of the WJ-R/BAT-R, the respective 7-test BCA-Standard and 14-test BCA-Extended cluster scores are based on the simple arithmetic average of each set of scores, thus resulting in an equally weighted global IQ score.

Thus, differences between the global WJ-R/BAT-R and WJ III/BAT III IQ scores may occur as a function of the respective scores reflecting differential contributions of the broad Gf-Gc abilities as per the CHC theoretical model that underlies the batteries.

Below is the IQ Test CHC DNA Fingerprint comparison of the two respective editions of the WJ-R/BAT-R and WJ III/BAT III.  The weights presented for the WJ III/BAT III are the median (average) weights across all age groups.  The previously referenced ASB (see above) includes a table of the specific weights by age.

[double click on figure to enlarge]

Although the CHC composition of the respective global IQ scores did not change dramatically, there are enough differences by CHC ability to suggest that slightly different global IQ scores may be produced for the same individual depending on whether they took the WJ-R/BAT-R or the WJ III/BAT III (assuming proper administration, scoring, etc.).  Consistent with psychometric intelligence theory (aka., CHC theory), the WJ III/BAT III global IQ scores (GIA-Stnd; GIA-Ext) are more heavily weighted as per a subjects performance on the more g-loaded measures of Gf (fluid intelligence/reasoning), Gc (crystallized intelligence or comprehension-knowledge), and Glr (long-term storage and retrieval).  In contrast, abilities that are less cognitively demanding and more related to perceptual (Gv, Ga), speed (Gs), and short-term memory (Gsm) functioning contribute slightly less to an individuals WJ III/BAT III global IQ GIA score than was the case with the WJ-R/BAT-R.

If significant differences are found when comparing scores from the respective R/III editions of the WJ for an individual, examiners should review the Gf-Gc CHC test/cluster profiles to determine if some (or all) of the score differences might be related to the shift from an equally weighted global IQ score (WJ-R/BAT-R) to a differentially-weighted (WJ III/BAT III) global IQ score.  In theory, an individual could obtain very similar test-level scores on each battery, but because "all scores are not created equal" (in the estimation of general intelligence or g) in the case of the WJ III, a shift in the global GIA IQ scores may occur.

Other IQ Test CHC DNA Fingerprint comparisons can be found by clicking here.  More will be coming in the future.

[Conflict of interest note:  I am a co-author of the WJ III/BAT III]

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Thursday, October 02, 2008

BAT III Woodcock-Munoz Assessment Service Bulletin (ASB)

I was looking at the searches that led people to this blog and noticed a number of folks looking for information regarding the Batería III Woodcock-Muñoz.  In looking through my past posts I noticed only one post regarding the BAT III---a test review in APA Division 16's School Psychologist.

I realized that I did have access to an Assessment Service Bulletin (ASB) published by Riverside Publishing.  Below is the reference and a link to the PDf document.  I hope this helps those looking for additional information regarding the BAT III.

  • Schrank, F., McGrew, K., Ruef, M.,
    Alvarado, C., Muñoz-Sandoval, A. & Woodcock (2005). 
    Batería III Woodcock-Muñoz Assessment Service Bulletin
    Number 1:  Overview and Technical Supplement.  
    Itasca, IL: Riverside Publishing. (click to
    view)