IQ Scholar Spotlight: Dr. Linda Gottfredson

Another IQ Scholar Spotlight - Dr. Linda Gottfredson.

Dr. Gottfredson organized (and presented) at the recent 2009 (Dec) ISIR conference a symposium called:  Causal models that integrate literacy, g, and health outcomes:  A practical guide to more effective disease prevention and health promotion?  She is a highly regarded intelligence scholar who has a wide array of interests in the field of intelligence including (from her web page):

• Intelligence, health and everyday life
• Intelligence and social inequality
• Employment testing and job aptitude demands
• Affirmative action and multicultural diversity
• Career development and vocational counseling

The diversity of her interests is reflected in a wide range of publications (which can be found at her web page).  For example, her 1997 Intelligence article "Why g matters:  The complexity of everyday life" is one of the top 10 cited articles in the journal Intelligence.  She was also the lead author of an important 1977 Intelligence editorial (Mainstream science on intelligence: An Editoral with 52 signatories, history, and bibliogrpahy) in response to the controversial Bell Curve book.  Here most recent "in press" Intelligence publication is Arden, R., Gottfredson, L. S., Miller, G., & Pierce, A. (in press). Intelligence and semen quality are positively correlated.

I found the measurement/prediction issues raised at her symposium very interesting.  The bottom line is that in the field of health care/literacy, doctors expect (hope? pray?) for 100% compliance in patient follow-through in treatment recommendations, the taking of prescriptions, etc.  So...a central question is how to ascertain which patients need more assistance in understanding their health care.  How can we predict which patients will need additional or special instructions and/or follow-up?  Of course, as we all in the field of individual difference measurement know, the best available measures in intelligence can only explain up to 50+% of the variance of any outcome or dependent variable.  An interesting dilema.

I had the opportunity to chat with Dr. Gottfredson about this issue.  One of her interests is in finding (or developing) brief, ecologically valid measures of g to screen patients.  She articulated the need for measures that tap a patients ability to handle complex information processing (high g tests) but that do NOT appear to look like intelligence measures, seem more "real world" in terms of ecological validity, and that would be easy to administer and score.

I shared with her some unpublished g-factor loadings of all the WJ III tests (when cognitive and achievement tests are combined together).  These g-loadings were calculated at different age groups using principal components analysis.  A summary of the table I provided Dr. Gottfredson can be found by clicking here.  Of interest (in our discussions) was a test like Understanding Directions....a test where a subject follows an increasingly long and complex set of simple directions (e.g., point to.....now point to.....now point to....,then.....,but first......).  As can be seen in the attached table, it is a high g test that would appear to have ecological and face validity for this purpose.  I believe it is a high g test due to the complexity of language-based working memory demands placed on subjects.  This discussion (and material) is presented here to stimulate thought and discussion.  Readers not familiar with the task demands of the WJ III tests should click here.  [Conflict of interest - I'm a coauthor fo the WJ III].


Technorati Tags: psychology, educational psychology, school psychology, neuropsychology, cognition, IQ, IQ tests, intellligence, g, general intelligence, health literacy, WJ III, Woodcock Johnson, ISIR, IQ Scholar Spotlight

Detterman's laws of individual differences

Early in my career I ran across a tremendous tongue-in-check book chapter by Doug Detterman where he articulated Detterman's Laws of Individual Differences (click here to view--you will need to rotate in your pdf reader). Many of the laws make me laugh to this day. All serious individual difference psychologists (psychometrics, intelligence researchers, developers and users of intelligence tests) should read these from time-to-time....to regain perspective on research in this area. You can read them for yourself...but below are a few of my favorites:

Laws of statistical inertia

• Law II. Anything which exists can be measured incorrectly
• Law III. Incorrect measurements require intelligent application of appropriate statistics to be interpretable
• Law IV. It can't be done.
• Law VII. Everything is correlated with everything else.
• Law VIII. Never factor analyze anything - this is one of my absolute favorites, esp. his further explation.....it is impossible to conduct a factor analysis correctly on data which are completely suitable......determining an acceptable rotation has never been accomplished by anyone in the history of Western Civilization..it is impossible to name factors and still have friends...
  
• Law X. The less frequently used multivariate techniques...must be left to the experts.
• Law X (corrlary 1). There are no experts in the less frequently used multivariate techniques.
• Law XIII. The potential usefulness of any statistical technique is directly proportional to the impossibility of its correct application.

Laws of research strategy.

• Law XV. My area is best
• Law XVI. Always remember you are bringing religion to the heathen.
• Law XVIII (corralary 1). Awlays use models at least ten years old.
• Law XVIII (corralary 2). Never blame the model.

Laws of creative research interpretation

• Law XXI. Lacking reliability and/or validity, theorize.
• Law XXII. Having obtained reliability and/or validiy, theorize elaborately

And many others..............a classic in the field.

Technorati Tags: psychology, educational psychology, school psychology, individual differences, neuropsychology, education, cognition, intelligence, IQ, Dettermans Laws, ISIR

IQ (ISIR) Scholar Spotlight: Tim Keith - DASII CHC CFA and gender differences in abilities

Dr. Tim "Happiness is a latent variable" Keith presented at the 2008 ISIR conference. Tim is a tremendous scholar (and friend) with tremendous expertise in structural equation modeling. He is one of two people I turn to when I need help with running CFA models. He has completed some of the best CFA studies of the major individually administered intelligence batteries. I've collaborated with him on a number of g+specific abilities studies. More recenty he has been turning his atttention to using SEM methods to evaluate gender differences in latent CHC abilities (click the following links to view his recent published research with the WJ III - conflict of interest disclosure--I'm a coauthor of the WJ III).

At the ISIR conference he presented the same type of analysis of the Differential Abilities Scales--II (DAS-II) norm data. The figure below was the best fitting model. The model provides good support for CHC interpretation of the DAS-II. At the conference his primary focus was gender differences.

Briefly, Tim's gender analyses is summarized below:

• Females (5-17 years of age) were higher on Gs, Gsm, and Glr (actually the narrow ability of M6 - free recall memory)
• Males (5-17 years) higher on Gv
• No gender differences on Gc, Gf, or g.

[double click on image to enlarge]

IQ (ISIR) Scholar Spotlight: David Lohman--CogAT, NNAT, Ravens research

David Lohman presented at the 2008 ISIR conference. I've been a big fan of Lohman's work as much of it has direct application to the work of practicing school and educational psychologists. Lohman was a student of the late Richard Snow, whose work has had a significant work on my thoughts regarding non-cognitive factors important for school learning (see prior post today). Lohman is an author of the group CogAt (click here to see prior post re: study with WJ III). Aside from being an excellent applied psychometrician, Lohman has written papers on a wide variety of topics in educational psychology and intelligence. He is also very generous in making his various publications available for download at his web page.

At this conference he presented a paper comparing scores and norm characteristics from the CogAT, NNAT, and Ravens. The name of the paper and abstract (italics added by me) is below. The focus was on the use of nonverbal measures of intelligence in the identifcation of gifted students. The results presented were a bit disconcerting regarding possible technical issues with the norms of two of the tests---I've featured Lowman's conclusion in the abstract below. Lohman's research raises significant issues re: the accuracy of gifted identification via the NNAT and Ravens. Of course, and appropriately so, Lohman made it clear that his findings and research needed to recognize his potential conflict of interest as author of the CogAT, a direct competitor to the other tests, esp. the NNAT. It is refreshing to see such scholarly integrity in person.

• Ethnic Differences on Fluid Reasoning Tests: Is the NNAT the Panacea? David F. Lohman, University of Iowa

• Abstract: Nonverbal, figural reasoning tests such as the Raven Progressive Matrices are often used as markers for Gf in research on intelligence. These tests are also widely used in schools to help identify academically gifted students. The Naglieri Nonverbal Ability Test (NNAT) has been particularly popular following a recent report that in a large, representative sample of U.S. school children, it was found to identify equal proportions of high-scoring White, Black, and Hispanic students. Although questions have been raised about the integrity of the data analyses used in this study, the author of the study continues to defend it as the most important research yet conducted with the NNAT. The goal of this investigation was to compare the NNAT with two other nonverbal assessments: the Raven Progressive Matrices and the Nonverbal Battery of the Cognitive Abilities Test (CogAT). All three tests were administered by trained examiners in counterbalanced order to 1,200 children in grades K to 6 in an ethnically diverse school district. Results showed provided no support for the assertion that the NNAT reduced ethnic differences – either at the mean or at the tails of the distribution. Rather, ethnic differences were actually somewhat larger on the NNAT than on the other two tests. Furthermore, it was discovered that the variance of basic normative score on the NNAT (M = 100, SD = 15) substantially exceeded the reported value of 15 at all but one test level. Re-analyses of the standardization data for the NNAT confirmed this finding. A similar normative score on the Raven (computed from the most recent U.S. national norms) was 10 points too lenient. Consequences of invalid or outdated normative scores for research and practice are discussed.

If you are interested in learning more about this issue, you should check out his full length publication in Gifted Child Quarterly (which Lohman makes available from his web page). You can view a copy by clicking here. The reference citation is: Lohman, D. F., Korb, K., & Lakin, J. (2008). Identifying academically gifted English language learners using nonverbal tests: A comparison of the Raven, NNAT, and CogAT. Gifted Child Quarterly, 52, 275-296. Apparently this paper received the "Research Paper of the Year Award" from the National Association of Gifted Children.

The bottom line take-away: Buyer beware. Educators need to do their due diligence when evaluating and comparing psychometric instruments (group or individual) that impact important educational decisions regarding children.

[Conflict of interest disclosure - I'm a coauthor of the WJ III mentioned above, which is an instrument that competes with a different individually administered cognitive battery of the author of the NNAT, which was a focus of Lohman's presentation and paper].

ISIR post thoughts - live blogging was not an option

I attended the 9th Annual ISIR conference last week in Decatur, GA.  As usual, another great conference.  Kudos to Doug Detterman and the others who organized the program (click here find the program and names in a prior post).

In contrast to my last ISIR conference, I was unable to blog live due to the lack of a wifi signal in the conference room.  I've not yet posted any information as I didn't return until Sunday and it has taken a good day to get back to speed on my work. 

My plan is to now start sending out a series of posts.  Some may contain bits and pieces of reports and my thoughts regarding multiple presentations.  Others I plan to put in the form of IQ Scholar Spotlight posts.....reflecting the presence of a particular intelligence scholar at the conference.  I will do my best to capture some of the take-away messages I gleaned from the particular scholars presentation.

Be patient.  Blogging is only a hobby.  Bills need to be paid.

Technorati Tags: psychology, educational psychology, school psychology, neuropsychology, intelligence, IQ, cognition, IQ Scholar Spotlight, ISIR

IQ Scholar Spotlight: Ian Deary

Another IQs Corner IQ Scholar Spotlight - Dr. Ian Deary

Dr. Ian Deary (listed under IQs Corner IQ Scholar section) is prolific scholar in the study of human intelligence, probably most well known for his constant stream of publications from the Scottish Mental Survey follow-up studies (The Edinburgh-based follow-up studies of the Scottish Mental Surveys of 1932 and 1947.). His findings have highlighted very interesting, and sometimes surprising, links between early intelligence and later adult behavior and outcomes. More information can be found at Wikipedia.

I ran a search of his name in the IAP Reference Database and found over 80+ references (click here to view)

Technorati Tags: psychology, educational psychology, cognitive psychology, neuropsychology, intelligence, ISIR, IQs Corner, IQ Scholar Spotlight, developmental psychology

IQ Scholar Spotlight: David Geary

Another IQs Corner IQ Scholar Spotlight - Dr. David Geary

Dr. David Geary (listed under IQs Corner IQ Scholar section) is a tremendous researcher and thinker. I try to read every think he writes. I've been particularly interested in his excellent research on the cognitive skills related to the development of mathematical abilities---he is, IMHO, one of the top researchers in this area. His writings on evolutionary psychology, which recenty have focused on educational implications, are very thought provoking. I particularly enjoyed his recent article on "evolutionary aspects of math disabilities." A definite must scholar to keep tabs on. Click here for prior IQs Corner posts that have mentioned Geary.

Technorati Tags: psychology, educational psychology, school psychology, neuropsychology, cognitive, cognition, intelligence, evolution, evolutionary psychology, math, mathematics, learning disabilities, MLD, David Geary, IQs Corner, IQ Scholar, ISIR

IQ Scholar Spotlight: Stephen Bowden

I'm going to attempt to start another semi-irregular FYI topic post to IQs Corner....IQ Scholar Spotlight.  As you will notice on the left side of the blog, there is an area that includes links to prominent scholars in human intelligence (IQ Scholars).  You can click on names and go to their professional web pages and learn more about their research.  I must admit that I've been remiss in keeping this current...a situation I now hope to rectify.

Today I'm adding Dr. Stephen Bowden, University of Melbourne, who I met while in Australia presenting on the new Australian Adaptation of the WJ III.  Dr. Bowden will be independently analyzing the factor structure of the WJ III AUS norm data. 

Technorati Tags: psychology, educational psychology, school psychology, quantitative psychology, factor analysis, WJ III, Australia, Stephen Bowden, IQs Corner