From the #Cattell-Horn-Carroll (#CHC) #cognitive #intelligence theory archives: Photos of important 1999 Carroll, Horn, Woodcock, Roid et al. meeting in Chapel Hill, NC.

I was recently cleaning my office when I stumbled upon these priceless photos from a 1999 historical meeting in Chapel Hill, NC that involved John Horn, Jack Carroll, Richard Woodcock, Gale Roid, John Wasserman, Fred Schrank and myself).  The provenance (I’ve always wanted to use this word 😉) for the meeting is provided below the pictures in the form of extracted quotes from Wasserman (2019) and McGrew (2023) (links below), which I confirmed with John Wasserman via a personal email on August, 30, 2025.

The 1990 CHC-based WJ-R had already been published and the WJ III author team were nearing completion of the CHC-based WJ III (2001).  Unbeknownst to many is the fact that Woodock was originally planned to be one of the coauthors of the SB5 (along with Gale Roid), which explains his presence in the photo’s that document one of several planning meetings for the CHC-based SB5.  

I was also involved as a consultant during the early planning for the CHC-based SB5 because of my knowledge of the evolving CHC theory.  My role was to review and integrate all available published and unpublished factor analysis research on all prior editions of the different SB legacy tests. I post these pictures with the names of the people included in each photo immediately below the photo. No other comments (save for the next paragraph) are provided.  

To say the least, my presence at this meeting (as well as many other meetings with Carroll and Horn together, as well as with each alone, that occured when planning the various editions of the WJ’s) was surrealistic.  One could sense a paradigm shift in intelligence testing that was happening in real time during the meetings!  The expertise of the leading theorists regarding what became known as CHC theory, together with the expertise of the applied test developers of Woodcock and Roid, provided me with learning experiences that cannot be captured in any book or university course work. 

Click on images to enlarge.  

Be gentle, these are the best available copies of images taken with an old-school camera (not smart-phone based digital images)

(Carroll, Woodcock, McGrew, Schrank)

(Carroll, Woodcock, McGrew)

(Woodcock, Wasserman, Roid, Carroll, Horn)

(Wasserman, Roid, Carroll, Horn, McGrew)

(Carroll, Woodcock)

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“It was only when I left TPC for employment with Riverside Publishing (now Houghton-Mifflin-Harcourt; HMH) in 1996 that I met Richard W. Woodcock and Kevin S. McGrew and became immersed in the extended Gf-Gc (fluid-crystallized)/ Horn-Cattell theory, beginning to appreciate how Carroll's Three-Stratum (3S) model could be operationalized in cognitive-intellectual tests. Riverside had been the home of the first Gf-Gc intelligence test, the Stanford–Binet Intelligence Scale, Fourth Edition (SB IV; R. L. Thorndike, Hagen, & Sattler, 1986), which was structured hierarchically with Spearman's g at the apex, four broad ability factors at a lower level, and individual subtests at the lowest level. After acquiring the Woodcock–Johnson (WJ-R; Woodcock & Johnson, 1989) from DLM Teaching Resources, Riverside now held a second Gf-Gc measure. The WJ-R Tests of Cognitive Ability measured seven broad ability factors from Gf-Gc theory with an eighth broad ability factor possible through two quantitative tests from theWJ-R Tests of Achievement. When I arrived, planning was underway for new test editions – the WJ III (Woodcock, McGrew, & Mather, 2001) and the SB5 (Roid, 2003) – and Woodcock was then slated to co-author both tests, although he later stepped down from the SB5. Consequently, I had the privilege of participating in meetings in 1999 with John B. Carroll and John L. Horn, both of whom had been paid expert consultants to the development of the WJ-R” (Wasserman, 2019, p. 250)

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“In 1999, Woodcock brokered the CHC umbrella term with Horn and Carroll for practical reasons (McGrew 2005)—to facilitate internal and external communication regarding the theoretical model of cognitive abilities underlying the then-overlapping test development activities (and some overlapping consultants, test authors, and test publisher project directors; John Horn, Jack Carroll, Richard Woodcock, Gale Roid, Kevin McGrew, Fred Schrank, and John Wasserman) of the Woodcock–Johnson III and the Stanford Binet–Fifth Edition by Riverside Publishing” (McGrew, 2023, p. 3)

On the origin and evolution (from 1997 chapter to 2025 #WJV) of the #CHC #intelligence theories definitions: The missing CHC definition’s birth certificate

This is an updated version of an OBG (oldie but goodie) post originally made in 2017.  

The historical development of the CHC model of intelligence has been documented by McGrew (2005) and Schneider and McGrew (2012) and summarized by Kaufman and colleagues (Kaufman, 2009; Kaufman, Raiford & Coalson, 2016). Additional extensions and historical anecdotes were rececntly presented by McGrew (2023) in an article included in a special issue of the Journal of Intelligence focused on Jack Carroll’s tri-stratum theory @ 30 years. McGrew (2023) recommended that CHC theory should now be referred to as a group of CHC theories (i.e., a family of orthogonally correlated models) that recognizes the similarities and differences between the theoretical models of Cattell, Horn and Carroll.

An unexplained crucial, yet missing piece of the CHC story, is the origin of the original CHC broad and narrow ability definitions.  The CHC ability definition birth certificate, until recently, had not been revealed.  To fend off possible CHC “birther” controversies, I will now set the record straight again (as was first done in 2017) regarding the heritage of the past and current CHC definitions.

Given the involvement of both John Horn and Jack Carroll in revisions of the WJ-R and WJ III, which was the impetus for the combined CHC theory, it is not surprising that the relations between the “official” CHC ability definitions and the WJ tests were “reciprocal in nature, with changes in one driving changes in the other” (Kaufman et al., 2016, p. 253).  Furthermore, “the WJ IV represented the first revision in which none of the original CHC theorists was alive at the time of publication, producing and imbalance in this reciprocal relationship—-“the WJ IV manuals now often served as the official source for the latest CHC theory and model of cognitive abilities (J. Schneider, personal communication, March 15, 2015)” (Kaufman et al., 2016; p. 253).  Kaufman et al. noted that with the development of subsequent non-WJ CHC assessment and interpretation frameworks (e.g., Flanagan and colleagues CHC cross-battery assessment; Miller’s integrated school neuropsychology/CHC assessment model), some confusion has crept into what represents the authoritative “official” and “unofficial” definitions and sources.  

In Schneider & McGrew (2012) and Schneider & McGrew (2018), the incestuous nature of the evolution of the CHC definitions continued by building primarily on the McGrew (2005) definitions, which in turn were reflected in the 2001 WJ III manuals, which in turn drew from McGrew (1997).  In my original 2017 post regarding this topic, it was judged time to divorce the official CHC definitions from the WJ series and authors (particularly myself, Kevin McGrew). 

However, the CHC birth certificate is still often questioned.  Did the CHC definitions magically appear?  Did they come down in tablet form from a mountain top?  After the Cattell-Horn and Carroll models were first married by McGrew (1997), were the definitions the result of some form of immaculate conception?  Did  McGrew (1997) develop them unilaterally?  

Here is….the “rest of the story.”  

The original CHC definitions were first presented in McGrew’s (1997) chapter where the individual tests from all major intelligence batteries where classified as per the first integration of the Cattell-Horn and Carroll models of cognitive abilities (then called a “proposed synthesized Carroll and Horn-Cattell Gf-Gc framework”).  In order to complete this analysis, I (Kevin McGrew) needed standard CHC broad and narrow definitions—but none existed.  I consulted the Bible…Carroll’s Human Cognitive Abilities (1993).

I developed the original definitions (primarily the narrow ability definitions) by abstracting definitions from Carroll’s (1993) book.  After completing the first draft of the definitions, I sent them to Carroll. He graciously took time to comment and edit the first draft. I subsequently revised the definitions and sent them back. Jack and I engaged in several iterations until he was comfortable with the working definitions. As a result, the original narrow ability definitions published in McGrew (1997) had the informal stamp of approval of Carroll, but not of Horn. The official CHC definition birth certificate should list Carroll and McGrew as the parents.  

Since then the broad and narrow CHC ability definitions have been parented by McGrew (McGrew & Woodcock, 2001; McGrew, 2005; McGrew et al., 2014) and more recently, uncle Joel Schneider (Schneider & McGrew, 2012; Schneider & McGrew, 2018). The other WJ III and WJ IV authors (Mather, Schrank, and Woodcock) served as aunts and uncles at various points in the evolution of the definitions, resulting in the current “unofficial” definitions being in the WJ IV technical manual (McGrew et al., 2014) and the Schneider & McGew (2018) chapter. 

With new data-based insights from the the validity analysis of the norm data from the forthcoming WJ V (LaForte, Dailey & McGrew, 2025, in preparation), the WJ V technical manual will provide, yet again, a slightly new and improved set of CHC definitions.  Stay tunned.

No doubt the WJ V 2025 updated CHC definitions will still have a clear Carroll/McGrew, WJ III /WJ IV/WJ V and Joel Schneider genetic lineage (McGrew, 1997—>McGrew & Woodcock, 2001—>McGrew, 2005—>Schneider & McGrew, 2012—>McGrew et al., 2014—>Schneider & McGrew, 2012, 2018).  We (Schneider and McGrew) are reasonably comfortable with this fact.  However, we hope that the WJ—>WJ V set of CHC definitions will eventually move out of the influence of the WJ/CHC house and establish a separate residence, identity, and process for future growth.  I am aware that Dr. Dawn Flanagan and colleagues are working on a new revision of their CHC cross-battery book and related software and will most likely include a new set of revised defintions.  Perhaps a melding with the WJ V technical manual definition appendix with the work of Flanagan et al. would be a good starting point.  Perhaps some group or consortium of interested professionals could be established to nurture, revise, and grow the CHC defintions.