This is a small presentation I developed a number of years ago demonstrating how appropriate CHC test classifications requires cross-battery (joint) factor analysis with sufficient markers of relevant CHC abilities to correctly determine the CHC broad abilities measured by tests. This conceptual explanation demonstrates how the Wechsler Digit Span, Coding and Arithmetic tests, which for years were incorrectly classified as measuring a “Freedom from Distractibility” factor/ability due to reliance on atheoretical within-battery factor analysis results. These three tests only became correctly classified (as per CHC theory) when sufficient indicators of the broad CHC abilities (esp. Gsm, Gs, and Gq) were included in cross-battery factor studies. I use the analogy of the breadth of people present at class reunions to illustrate the limitations of within-battery factor analysis studies and the strengths of CHC (theory-based) cross-battery (joint) factor analysis.

1. Within and Cross-Battery Wechsler “Class Reunion” Factor Analysis Explanation Kevin S. McGrew 7-18-08 This is a small presentation I developed a number of years ago demonstrating how appropriate CHC test classifications requires cross-battery (joint) factor analysis with sufficient markers of relevant CHC abilities to correctly determine the CHC broad abilities measured by tests. This conceptual explanation demonstrates how the Wechsler Digit Span, Coding and Arithmetic tests, which for years were incorrectly classified as measuring a “Freedom from Distractibility” factor/ability due to reliance on atheoretical within-battery factor analysis results. These three tests only became correctly classified (as per CHC theory) when sufficient indicators of the broad CHC abilities (esp. Gsm, Gs, and Gq) were included in cross-battery factor studies. I use the analogy of the breadth of people present at class reunions to illustrate the limitations of within-battery factor analysis studies and the strengths of CHC (theory-based) cross-battery (joint) factor analysis.

2. THE 1974 WISC-R CLASS REUNION Information Similarities Vocabulary Comprehension Pic. Completion Pic. Arrangement Block Design Obj. Assembly Mazes Arithmeti Digit Span Coding Verbal Comp. Clique - Gc Per. Organ. Clique - Gv FFD - not really a clique - “ our friends didn’t show”

3. WISC-III REUNION: 17 YEARS LATER Information Similarities Vocabulary Comprehension Pic. Completion Pic. Arrangement Block Design Obj. Assembly Mazes Verbal Comp. Clique - Gc Per. Organ. Clique - Gv Arithmeti Digit Span FFD - not really a clique - “ our friends didn’t show” Coding Symbol Search Proc. Speed Clique - Gs

4. THE JOINT WISC-III/WJ-R REUNION Coding Symbol Search Proc. Speed Clique - Gs Vis. Matching Cross Out Information Similarities Vocabulary Comprehension Verbal Comp. Clique - Gc Pict. Vocab. Oral Vocab. Pic. Completion Pic. Arrangement Block Design Obj. Assembly Mazes Per. Organ. Clique - Gv Vis. Closure Pict. Recogn. Arithmetic Calculation Applied Prob. Quant. Clique - Gq Digit Span Mem. Words Mem. Sent. STM Clique - Gsm

5. Results of CHC Confirmatory Cross-Battery Factor Analysis of WISC-R and WJ-R Information Similarities Vocabulary Comprehension Pic. Completion Pic. Arrangement Block Design Obj. Assembly Mazes Arithmetic Gc Gv Calculation Applied Prob. Pict. Vocab. Oral Vocab. Vis. Closure Pict. Recogn. Gq Note: WJ-R tests are indicated by bold rectangles Coding Gs Vis. Matching Cross Out Digit Span Mem. Words Mem. Sent. Gsm Incomplete Wds. Sound Blending Anal.-Synth. Conc. Form. Ga Gf Vis.Aud. Lrng Mem. for Names Glr

6. The Use Of Factor Analysis To Classify Abilities Measured By Tests Within-battery factor analysis Information Similarities Vocabulary Comprehension Pic. Completion Pic. Arrangement Block Design Obj. Assembly Mazes Arithmeti Digit Span Coding Verbal Comp. Clique - Gc Per. Organ. Clique - Gv FFD - not really a clique - “ our friends didn’t show”

7. Information Similarities Vocabulary Comprehension Pic. Completion Pic. Arrangement Block Design Obj. Assembly Mazes Arithmetic Gc Gv Calculation Applied Prob. Pict. Vocab. Oral Vocab. Vis. Closure Pict. Recogn. Gq Note: WJ-R tests are indicated by bold rectangles Coding Gs Vis. Matching Cross Out Digit Span Mem. Words Mem. Sent. Gsm The Use Of Factor Analysis To Classify Abilities Measured By Tests Cross-battery factor analysis Incomplete Wds. Sound Blending Anal.-Synth. Conc. Form. Ga Gf Vis.Aud. Lrng Mem. for Names Glr