Sunday, March 05, 2006

IQ PREPLOG: CHC abilities and effects on reading skills--beyond g--some specific abilities important

This is an IQ PREPLOG post. The following manuscript is now "in press" and can be viewed by clicking here.

Floyd, R., Keith, T., Taub, G. McGrew, K. (2006). Cattell–Horn–Carroll Cognitive Abilities and Their Effects on Reading Decoding Skills: g Has Indirect Effects, More Specific Abilities Have Direct Effects. School Psychology Quarterly (in press 2-28-06)

  • Previous research has indicated the importance of several cognitive abilities to the acquisition and development of reading decoding skills. The findings from such research may be limited because some abilities, such as general intelligence (g), frequently have been omitted from analyses. Drawing on the ability taxonomy of the Cattell–Horn–Carroll (CHC) theory, this study employed structural equation modeling to examine the effects of CHC abilities on reading decoding skills using 5 age-differentiated subsamples from the standardization sample of the Woodcock–Johnson III (Woodcock, McGrew, Mather, 2001). Using the Spearman Model including only g, strong direct effects of g on reading decoding skills were demonstrated at all ages. Using the Two-Stratum Model including g and broad abilities, direct effects of the broad abilities Long-Term Storage and Retrieval, Processing Speed, Crystallized Intelligence, Short- Term Memory, and Auditory Processing on reading decoding skills were demonstrated at select ages. Using the Three-Stratum Model including g, broad abilities, and narrow abilities, direct effects of the broad ability Processing Speed and the narrow abilities Associative Memory, Listening Ability, General Information, Memory Span, and Phonetic Coding were demonstrated at select ages. Across both the Two-Stratum Model and the Three-Stratum Model at all ages, g had very large but indirect effects. The findings suggest that school psychologists should interpret measures of some specific cognitive abilities when conducting psychoeducational assessments designed to explain reading decoding skills.

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1 comment:

Anonymous said...

Thanks for making this available, Kevin. This is so important when analyzing cognitive testing data and comparing to a student's processing of written material in making a case for a reading disability. I'm going to be reviewing the article in depth for those age ranges--have a couple of interesting cases right now where this will be very useful.