WISC-IV VS. RIAS: Will the Real IQ Please Stand Up!! A 2-year study comparing the two IQ instruments.

HYPOTHESIS RESEARCHER HYPOTHESIZED THAT THE RIAS WOULD SCORE HIGHER GIVEN THE ADDITIONAL PSYCHOMOTOR PROCESSING AND WORKING MEMORY FACTORS ON THE WISC-IV.

PLEASE REFER TO THE GAI DATA AND SUPPLENTAL TABLES FOR WISC-IV UPDATES. ADDITIONALLY, BOTH INSTRUMENTS MEASURE DIFFERENT CONSTRUCTS. THEREFORE, WE ARE MEASURING SIMILAR YET DIFFERENT ASPECTS OF COGNITION. “SQUARE FEET VS. CUBIC FEET” THINKING.

WISC and RIAS Verbal Comparisons 3 Subtests General fund of knowledge Verbal associative reasoning Vocabulary – expressive language Moral judgment, common sense, independent thinking RIAS 2 Subtests General fund of knowledge Verbal associative reasoning Vocabulary – one-word responses

WISC and RIAS Comparisons Performance IQ 3 Subtests Nonverbal associative and categorical reasoning Analyze and synthesize abstract visual information RIAS 2 Subtests Nonverbal associative and categorical reasoning Deduce essential elements missing in pictures from gestalt

WISC and RIAS Comparisons – Working Memory 0 Subtests Not part of the CIX WISC 2 Subtests measuring attention, concentration, sequencing, and short-term auditory memory

WISC and RIAS Comparisons – Processing Speed 0 Subtests Timed nonverbal tasks involving cognitive efficiency and speed w/o paper and pencil WISC 2 Subtests Graphomotor processing speed involving timed paper and pencil tasks Visual-motor coordination Concentration and visual memory

DESIGN Random Select Selection Select ‘fine’ Psychologists from St. Johns County school district randomly selected students ranging from 6-16 years of age and administered both the WISC-IV and RIAS IQ instruments. All students were referred by the CST. Abundance of data from the 2005-06 SY. Psychologists gave raw data to researcher to tabulate.

DESIGN ONLY THE AGE OF THE STUDENTS WAS USED AS “PREDICTOR VARIABLE.” AGES RANGED FROM 6-16. MAJORITY OF STUDENTS WERE IN THE 7 YR. OLD THROUGH 10 YR. OLD RANGE.

RACE AND GENDER NOT USED FOR COMPARISONS GIVEN LIMITED NUMBER Only less than a handful of minority African American and Hispanics tested. Gender not a major contributing factor on how data is to be used.

Pearson Correlation Coefficient The Full Scale IQ’s and the Factor Scores will be compared to check for correlation coefficients. WESSA.NET was used as the software program to calculate Pearson Product Moment Correlation Coefficients.

TOTAL N = 121 BREAKDOWN BY AGE N = Number 6 YEAR OLDS 09 ___________________________________ TOTAL SAMPLE N = 121

Correlations Between the RIAS Index Scores and the WISC-III IQ Scores – Reynolds Manual pg. 105. Verbal IQ Performance IQ Working Memory Processing Speed FSIQ RIAS Index Mean IQ Mean IQ 108.2 104.6 ------ 107.8 VIX 102.1 .86 ---- NIX 101.0 .33 CIX 100.3 .76

Perceptual Organization Pearson Correlations Between the RIAS Index Scores and the WISC-IV Factor Scores Ages 6 – 16 (N = 121) WISC-IV IQ Verbal Comprehension Perceptual Organization Working Memory Processing Speed FSIQ RIAS Index Mean IQ Mean IQ 96.2 95.8 89.7 90.7 92.2 VIX 99.9 .83 ---- NIX 104.1 .54 CIX 101.6 .62 .45 .79

Perceptual Organization Pearson Correlations Between the RIAS Index Scores and the WISC-IV Factor Scores – Primary Grade Ages 7 – 9 (N = 83) WISC-IV IQ Verbal Comprehension Perceptual Organization Working Memory Processing Speed FSIQ RIAS Index Mean IQ Mean IQ 99.0 100.0 91.7 93.4 95.6 VIX 102.5 .83 ---- NIX 105.4 .42 CIX 103.7 .58 .36 .75

Limitations of Study The sample was taken from students already referred for assessment. Approximately 90% were referred for Special Needs/reevals and 10% for Gifted evaluation. Majority of sample from 7-10 year old range. Older MS/HS population not adequately represented in sample. Majority of sample Caucasian and from Middle Class SES. Minorities and/or Low SES not adequately represented.

CONCLUSIONS RIAS tends to score approximately 10 points higher than the WISC-IV on global cognitive ability measure. Strongest correlations between RIAS VIX and WISC-IV VC of .83 followed by RIAS CIX and WISC-IV FSIQ of .79 correlation. Weakest link between RIAS CIX and WISC-IV PS of .45 correlation.

IMPLICATIONS The range of scores among all age groups tends to favor the RIAS in regards to scoring higher on both ends of the distribution. This may influence ESE placement decisions. Working Memory and Processing Speed tends to depress the WISC FSIQ by approximately 4 points. This may influence ESE placement decisions. Even though RIAS scores higher on all measures and through all age groups, both instruments correlate fairly well with a high degree of confidence when comparing global IQ scores. This indicates fairly good reliability and validity.

FUTURE RECOMMENDATIONS Assess minority populations and compare results with current data. Assess Low SES w/o regard for race and compare with current data. Assess middle and high school students to a larger extent. Assess pre-K students with WPPSI-III and RIAS and compare data.

Excerpt from Dr. Cecil Reynolds e-mail ….. It is clear the difference is really in the nonverbal sections of the tests, just as we have argued for some time.  The WISC-IV in my view confounds nonverbal intelligence with a host of tangentially related factors (speed confounded with motor for example, and the differential acquiescence of kids .. to work as quickly as they can, etc.), especially for referral samples wherein you also see a far higher incidence of mild motor issues.  I think the RIAS gives a more accurate view of NV intelligence for these kids and that seems to be your conclusion as well—we do not see this difference in nonreferred samples—random samples of normal kids score at about the same level on both.      Cecil R. Reynolds, PhD Professor of Educational Psychology Professor of Neuroscience