Monday, August 29, 2005

PREPLOG posts: Two CHC profile manuscripts

This is a PREPLOG fyi post about two recent CHC-related manuscripts. Contact Dr. Randy Floyd ( if you have any questions or requests for additional information.

  • Bergeron, R. & Floyd, R. (2005). Broad Cognitive Abilities of Children with Mental Retardation: An Analysis of Group and Individual Profiles. Manuscript submitted for publication.
  • Floyd, R. & Alfonso, R. (2005). Cattell–Horn–Carroll Cognitive Ability Profiles of Poor Comprehenders. Manuscript submitted for publication

Broad Cognitive Abilities of Children with Mental Retardation: An Analysis of Group and Individual Profiles

This study investigated the group and individual broad ability profiles of children with mental retardation (MR) and a matched sample of children with average achievement using the 7 Cattell–Horn–Carroll (CHC) factor clusters from the Woodcock–Johnson III Tests of Cognitive Abilities (Woodcock, McGrew, Mather, 2001). Results indicated that, as a group, the ranked performance of the children with MR on the CHC factor clusters was largely consistent with the clusters’ g loadings. When compared to the average-achieving matches, the children with MR scored lower on all CHC factor clusters, but the groups displayed different patterns of performance. Despite normative deficiencies in IQs, individual children with MR demonstrated a wide range of performance across measures. Implications for assessment and diagnosis are discussed.

Cattell–Horn–Carroll Cognitive Ability Profiles of Poor Comprehenders

This study examines cognitive ability profiles of children with specific age-based normative weaknesses in reading comprehension and compares those profiles to the profiles of (a) children with at least average achievement in reading comprehension, reading decoding skills, and mathematics and (b) children with low achievement across all three achievement areas. When compared across nine cognitive ability composite scores derived from Cattell–Horn–Carroll theory and measured by the Woodcock–Johnson III (Woodcock, McGrew, & Mather, 2001), groups differed in overall level of performance. When individual abilities were considered, the poor comprehenders scored significantly lower than the average achievement group on all nine abilities and significantly lower than the normative population on all abilities except Processing Speed and Long-Term Retrieval. In contrast, the poor comprehenders also scored significantly higher than the low achievement group on all abilities except for Visual–Spatial Thinking and Phonemic Awareness. Although the poor comprehenders as a group scored lowest on language- and knowledge-based abilities, review of the profiles of individual poor comprehenders revealed no consistent pattern of performance across cognitive abilities.

Friday, August 26, 2005

What is your B-IQ - Blog IQ?

Where do you stand in your understanding of blogs? I just stumbled across a brief Blog IQ test that may be of interest if you want to know your blog domain-specific knowledge.

New Charles "Bell Curve" Murray IQ/race/gender manuscript

This is an FYI post regarding an on-line manuscript posted today at the Commentary Magazine web page.

Charles Murrary, co-author of the contentious and widely reviewed/critiqued Bell Curve IQ book, has today published new comments and conclusions (The Inequity Taboo) regarding his position and reading of the controversial race/gender/intelligence literature.

Please note that the input he received (from well as other scholars) regarding this manuscript (in his "notes" section) does not imply endorsement of any part of the manuscript.
  • "My thanks go to Michael Ashton, Thomas Bouchard, Gregory Carey, Christopher DeMuth, David Geary, Linda Gottfredson, Arthur Jensen, John Loehlin, David Lubinski, Kevin McGrew, Richard McNally, Derek Neal, Steven Pinker, Philip Roth, Philippe Rushton, Sally Satel, Christina Hoff Sommers, Hua Tang, Marley Watkins, Lawrence Weiss, and James Q. Wilson for responding to questions or commenting on drafts. Their appearance on this list does not imply their endorsement of anything in the essay."
It appears that the topic of race and IQ may be heating up again. See two recent FYI blog posts (one; two) regarding a recent special issue of an APA journal that dealt exclusively with this topic.

Thursday, August 25, 2005

On-line intelligence and assessment literature database

Since 1994 I have been maintaining, and continually updating, a computerized database of literature (IAP Reference Database) selected because of its relevance to psychological assessment, theories of intelligence, measurement, and applied psychometric methods. All social and behavioral sciences journals listed in Current Contents are reviewed on a weekly basis and selected references are imported into the system. This has been occurring since 1994. The current database includes over 16,000 records.

This is a good database for locating contemporary literature in interest areas of this blog. If you want to receive the weekly "FYI" updates (that eventually are uploaded to the on-line DB 4-6 times a year), join the IAP CHC listserv. This listserv currently has 744 members.

As an example, I just completed a search using the phrase (with quotation marks) "working memory." 272 different references were returned. Below is a sample (the first five returned)

  • Conlin,J.A., Gathercole,S.E., and Adams,J.W. "Children's working memory: Investigating performance limitations in complex span tasks." Journal of Experimental Child Psychology 90, no. 4 (2005): 303-317.
  • Conway,A.R.A., Kane,M.J., Bunting,M.F., Hanbrick,D.Z., Wilhelm,O., and Engle,R.W. "Working memory span tasks: A methodological review and user's guide." Psychonomic Bulletin and Review (2005).
  • Fink,A. and Neubauer,A.C. "Individual differences in time estimation related to cognitive ability, speed of information processing and working memory." Intelligence 33, no. 1 (2005): 5-26.
  • Gathercole,S.E., Tiffany,C., Briscoe,J., and Thorn,A. "Developmental consequences of poor phonological short-term memory function in childhood: a longitudinal study." Journal of Child Psychology and Psychiatry 46, no. 6 (2005): 598-611.
  • Hall,M.D. and Blasko,D.G. "Attentional interference in judgments of musical timbre: Individual differences in working memory." Journal of General Psychology 132, no. 1 (2005): 94-112.
Keywords: CHC teaching tool

Multiple regression and beyond - Tim Keith book

Although I have yet to receive my copy, I can't wait until I receive my copy of Multiple Regression and Beyond by Timothy Z Keith. I have had the honor of working with Tim on a number of manuscripts and research projects. He is THE stat guy I always consult when I need complex multivariate statistics explained to me on a more conceptual level. He is the master in explaining complex statistics.

I would urge the stat/methodologists blog readers to give this book a serious look. Comments (from the back of the book) are provided below.

  • Multiple Regression and Beyond offers a conceptually oriented introduction to multiple regression (MR) analysis, along with more complex methods that flow naturally from multiple regression: path analysis, confirmatory factor analysis, and structural equation modeling. By focusing on the concepts and purposes of MR and related methods, rather than the derivation and calculation of formulae (the “plug and chug” approach), students learn more clearly, in a less threatening way. As a result, they are more likely to be interested in conducting research using MR, CFA, or SEM — and are more likely to use the methods wisely.
  • This is undoubtedly the most readable book about multiple regression I have ever used. My students found it clear and understandable. Keith writes in a clear style that is designed to engage students rather than alienate them. The emphasis is on conceptual understanding rather than mathematical proofs. Formulas are used when ne essary, but Keith takes care not to drown students in a sea of algebra. The aim throughout is to empower students to make the decisions that they will need to make in thier own research. Larry Greil, Alfred University
  • Keith's approach is a “conceptually oriented introduction” to multiple regression. None of the negative connotations of that phrase apply here. Keith's coverage de-emphasizes complex mathematics yet is committed to a rigorous, model-building use of multiple regression in research data analysis. . . . Material that can be quite difficult and confusing for students is covered with sufficient depth and clarity so that many issues will make considerably more sense to students than they usually do. Robert J. Crutcher, University of Dayton

Saturday, August 20, 2005

IQ tests and gifted: Piittsburgh Post-Gazette article

The role of intelligence testing in the idenfication of gifted individuals made the news in the Pittsburgh Post-Gazette. The article headline (with URL link) is listed below.

Working memory and Gf - is complexity necessary?

More on Gf and working memory (I think I'm perseverating this morning).

Below is an interesting article that suggests that highly Gf/g predictive working memory tasks do NOT need to require complex cognitive processing. Rather, simple working memory tasks are as strongly related to higher-level cognitive processing if they are designed to place significant demands on executive-controlled attention. This finding is consistent with the exectuive-controlled attention working memory model of Engle and Kane (see prior post for brief explanation and link to their home page)

Lepine, R. & Barrouillet, P. What makes working memory spans so predictive of high-level cognition? Psychonomic Bulletin & Review 2005, 12 (1), 165-170

  • Working memory (WM) span tasks involving a complex activity performed concurrently with item retention have proven to be good predictors of high-level cognitive performance. The present study demonstrates that replacing these complex self-paced activities with simpler but computer-paced processes, such as reading successive letters, yields more predictive WM span measures. This finding suggests that WM span tasks evaluate a fundamental capacity that underpins complex as well as elementary cognitive processes. Moreover, the higher predictive power of computer-paced WM span tasks suggests that strategic factors do not contribute to the relationship between WM spans and high-level cognition.

Article highlights
  • A popular hypothesis regarding the strong working memory (Gsm-MW) and Gf/g relationship has been that working memory measures assesses a “fundamental capacity required by complex activities, which is conceived of as a capacity to control attention (Engle, Kane, & Tuholski, 1999) or to supervise and coordinate multiple-system functioning (Baddeley, 1990). Consequently, the activities included as processing components in WM span tasks are usually selected from those thought to require a high level of executive control (e.g., problem solving, reading comprehension, reasoning, mental calculation). The underlying idea is that more controlled and complex activities provide better WM span measures because complex activities tap the limited pool of cognitive resources sufficiently to disrupt maintenance and permit an accurate measure of WM capacity.”
  • The current investigation sought to ascertain if “complexity of the processing component of WM span tasks necessary to disrupt maintenance and accurately assess WM capacity?” The authors cite research that has shown that “very simple activities included as processing components in WM span tasks have an equally detrimental effect on recall as do complex activities, provided that they are not self-paced but computer-paced…the authors accounted for this effect by proposing that simple but time-constrained activities capture a sufficient amount of attention to disrupt the maintenance of items to be recalled.
  • The current study suggested that highly predictive working memory tasks do not necessarily need to require complex processing. The author’s state:
    • A first conclusion, therefore, is that the complexity of the processing component in most of the traditional WM span tasks (reading span, operation span, alphabet recoding, and ABCD) is a superfluous characteristic. In fact, self paced WM span tasks require complex activities to induce the necessary time pressure that is inherent to their structure.
    • The second conclusion is that the predictive value of the traditional WM spans does not stem from their capacity to assess an ability to strategically cope with the demands of complex span tasks—which would also be involved in any complex activity—because when the possibility of dealing strategically with the task is reduced by computer-paced presentation, the predictive value is increased. This does not mean that mnemonic strategies for encoding and maintaining memory items are unimportant in complex spans (McNamara & Scott, 2001). However, our results show that complexity and strategies do not contribute to the predictive value of WM spans but rather introduce more noise than information into their relationship with high-level cognition.
    • This conclusion has theoretical and practical implications. The predictive power of span tasks with simple processing components suggests that WM tasks measure some fundamental and general capacity involved in both elementary and complex cognitive processing.
    • The current study supports the controlled-attention view of working memory. The results are consistent with “models of WM that conceive of cognitive resources as a kind of mental energy required to produce activation (Engle, Cantor, & Carullo, 1992; Just & Carpenter, 1992; Lovett, Reder, & Lebière, 1999). This result is also in line with the time-based resource-sharing model (Barrouillet et al., 2004), which assumes, following Anderson (1993) and Cowan (1995), that this fundamental capacity is attentional.

Working memory - more on Gf connection

As indicated by a number of prior posts ("Berlin BIS model of intelligence--material to review"; "g, working memory, specific CHC abilities and achievement") regarding the relationship between working memory (Gsm-MW) and fluid reasoning (Gf) or g, there is no shortage of contemporary research that continues to investigate the interesting relationship between higher-level cognitive processing and working memory. Below is a brief summary of yet another research article that sheds light on the possible reasons for the working memory/Gf/g relation.

Buehner, M., Krumm, S., & Pick, M. (2005). Reasoning=working memory ≠ attention. Intelligence, 33(3), 251-272.

  • The purpose of this study was to clarify the relationship between attention, components of working memory, and reasoning. Therefore, twenty working memory tests, two attention tests, and nine intelligence subtests were administered to 135 students. Using structural equation modeling, we were able to replicate a functional model of working memory proposed by Oberauer, Suess, Wilhelm, and Wittmann (2003) [Oberauer, K., Suess, H.-M., Wilhelm, O., & Wittmann, W. W. (2003). The multiple faces of working memory: Storage, processing, supervision, and coordination. Intelligence, 31, 167-193]. The study also revealed a weak to moderate relationship between the "selectivity aspect of attention" and working memory components as well as the finding that "supervision" was only moderately related to "storage in the context of processing" and to "coordination". No significant path was found from attention to reasoning. Reasoning could be significantly predicted by "storage in the context of processing" and "coordination". All in all, 95% of reasoning variance could be explained. Controlling for speed variance, the correlation between working memory components and intelligence did not decrease significantly.
Major findings
  • Oberauer, Suess, Wilhelm, and Wittmann’s (2000, 2003) model of working memory hypothesizes that working memory can be separated into two facets: a content facet (contains verbal/ numerical material and figural/spatial material) and a functional facet (separated into the components of storage in the context of processing, coordination, and supervision.
    • A characteristic storage task is a dual task, where participants have to remember words, then perform another task and finally recall the remembered words. This factor is similar to the updating and working memory capacity of Miyake, Friedman, Emerson, Witzki, Howerter, and Wager (2000) and Engle, Tuholski, Laughlin, and Conway (1999).
    • Coordination is the ability to build new relations between elements and to integrate relations into structures (Oberauer et al., 2003, p. 169).
    • Supervision involves the monitoring of ongoing cognitive processes and actions, the selective activation of relevant representations and procedures, and the suppression of irrelevant, distracting ones.
  • The variance explained by working memory components (especially storage in the context of processing and coordination) on Gf was 95% regarding the latent factors. Storage in the context of processing was the best predictor of Gf. It was revealed that coordination is also a significant predictor of Gf. Supervision and the selectivity aspect of attention had only little or no impact on Gf.
  • The excellent global-fit confirmed the structure of working memory found by Oberauer et al. (2003). However, the content factors could not be confirmed. This might be due to the reduced standard deviations and (consequently) lower reliabilities of some working memory tasks.

Quote to note - ideas

"One can live in the shadow of an idea without grasping it"

  • Elizabeth Bowen, quoted in the Associated Press.

Sunday, August 14, 2005

Journal awareness - Cognitive Neuropsycholgy

FYI - journal awareness. Cognitive Neuropsychology

Record 1 of 7
Authors C Becker, MA Elliott, T Lachmann
Title Evidence for impaired visuoperceptual organisation in developmental dyslexics and its relation to temporal processes
Full source Cognitive Neuropsychology, 2005, Vol 22, Iss 5, pp 499-522

Record 2 of 7
Authors AD Smith, ID Gilchrist
Title Within-object and between-object coding deficits in drawing production
Full source Cognitive Neuropsychology, 2005, Vol 22, Iss 5, pp 523-537

Record 3 of 7
Authors GW Humphreys, EME Forde
Title Naming a giraffe but not an animal: Base-level but not superordinate naming in a patient with impaired semantics
Full source Cognitive Neuropsychology, 2005, Vol 22, Iss 5, pp 539-558

Record 4 of 7
Authors M Arguin, D Bub
Title Parallel processing blocked by letter similarity in letter-by-letter dyslexia: A replication
Full source Cognitive Neuropsychology, 2005, Vol 22, Iss 5, pp 589-602

Record 5 of 7
Authors W Ziegler
Title A nonlinear model of word length effects in apraxia of speech
Full source Cognitive Neuropsychology, 2005, Vol 22, Iss 5, pp 603-623

Record 6 of 7
Authors T Shallice, N Venable, RI Rumiati
Title Dissociable distal and proximal motor components: Evidence from perseverative errors in three apraxic patients
Full source Cognitive Neuropsychology, 2005, Vol 22, Iss 5, pp 625-639

Record 7 of 7
Authors M Meeter, JMJ Murre
Title TraceLink: A model of consolidation and amnesia
Full source Cognitive Neuropsychology, 2005, Vol 22, Iss 5, pp 559-587

Saturday, August 13, 2005

Prospective memory anc CHC theory

What is "prospective memory" and is it a CHC narrow ability or a mixture of CHC narrow abilities? Salthouse et al recently published an interesting CFA to help answer these questions and to investigate the importance of prospective memory in aging research. The above SEM path diagram captures the essence of a recent investigation of this construct (see reference citation and abtract below)

According to Satlhouse et al. "(2004:

  • "Prospective memory refers to remembering to do something in the future. Although studied only recently, it has become of particular interest to researchers on aging because it may be more important for many aspects of everyday functioning and the ability to live independently than retrospective memory, which concerns information or events from the past. A considerable literature on adult age differences in prospective memory has emerged in the past 10–15 years" (p. 1133).

Salthouse, T. A., Berish, D. E., & Siedlecki, K. L. (2004). Construct validity and age sensitivity of prospective memory. Memory & Cognition, 32(7), 1133-1148.


  • We administered four prospective memory tasks to 330 adults between 18 and 89 years of age to investigate the relationship among the measures of performance in the four tasks, as well as the relationship of the prospective memory measures to age, other cognitive abilities, and noncognitive factors. The four prospective memory variables were found to exhibit both convergent and discriminant validity, indicating that prospective memory ability appears to represent a distinct dimension of individual differences. The prospective memory construct was significantly related to other cognitive abilities, such as executive functioning, fluid intelligence, episodic memory, and perceptual speed, but it was only weakly related to self-ratings of (primarily retrospective) memory and to personality traits. Although a substantial proportion of the age-related variance on the prospective memory construct was shared with other cognitive abilities, we also found some evidence of unique, statistically independent, age-related influences on prospective memory.

Sunday, August 07, 2005

CHC theories and models - clarification note

I'm often asked to explain how Cattell-Horn Gf-Gc and Carroll's Three-Stratum "theories" can be subsumed under a single theoretical umbrella....aka...CHC (Cattell-Horn-Caroll) Theory.

I've typically responded by indicating that CHC theory is the broad umbrella term for the most empirically supported psychometric structural theory of intelligence, and Cattell-Horn and Carroll simply have two different "flavors" of frameworks (models) for organizing and explaining the underlying structural elements. Stated more simply....CHC theory is the broad umbrella term that subsumes these two promient models.

I just ran across a quote that, I believe, supports my arm-chair distinction between the related concepts of a theory and a model. Below is a small section from the introduction of the following article. I think it supports the idea of a broad CHC theory under which there are two prominent specifications/organizations of the primary elements of the theory....aka, the Cattell-Horn and the Carroll models. I hope this helps.

Karr, C. A., & Larson, L. M. (2005). Use of theory-driven research in counseling: Investigating three counseling psychology journals from 1990 to 1999. Counseling Psychologist, 33(3), 299-326.

  • "The definition of theory used for this study was “a general principle formulated to explain a group of related phenomena” (Chaplin, 1985, p. 467). For the purposes of this study, a model was construed as “a description of the assumed structure of a set of observations” (Everitt &Wykes, 1999, p. 119). Although similar, the former utilizes a general tenet to explain related interactions, while the latter describes the expected observable interactions in more detail. By definition, theories and models are similar in function and scope. Forster (2000) stated that the best way to distinguish theories and models is to discuss each in conjunction with predictive hypotheses. In his conceptualization, the three are hierarchically arranged, with “theories at the most general level, models applied to concrete systems in the middle, and predictive hypotheses at the lowest level, which result from fitting models to data” (Forster, 2000, p. 233). He emphasized that “the essential point of this tripartite distinction is that predictive accuracy is a property of predictive hypotheses at the very bottom of the hierarchy, and is traded-off against the truth at the next level up—the level of models” (Forster, 2000, p. 233). In this way, both theories1 and models are tested by the utilization of tailored predictive hypotheses" (p. 300).

Friday, August 05, 2005

Coming out of the closet - looking forward to MN winter

I apologize to those who have been checking my blog with regularity the past month. I've NOT been able to post with any regularity. Frankly, summers seem to make me less productive. Yep...I'm willing to come out of the closet and admit that I, a Minnesota native for all but 2 years of my life, look forward to winters...........Because I can then FINALLY attend to all that scholarly stuff I've been wanting to do...analyze data and read journal articles on cold nights.

Yep...I must admit that despite the usual moaning and groaning about Minnesota winters, I find a silver lining to the cold and dark nights............time to get caught up on everything...Including this blog.

Seriously, I've now put "blog" on my MS Outlook calendar as a daily remind myself to nurture this pet project with more diligence. I will try hard.