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Reynolds Intellectual Assessment Scale (RIAS)
Supplemental: Mitochondrial Disease (Mito)
Short Description of Instrument

4 individually administered subtests, 2 assessing verbal intelligence; plus 2 supplementary memory scales. The test was designed to provide a unitary and valid assessment of g and components fluid and crystalized intelligence (based on Horn and Cattell model of intelligence).

Strengths/Weaknesses: Provides a rapid, comprehensive, and cost- effective assessment of intelligence and a screen of short-term memory. Normed for use across a broad age range, making it a good instrument for longitudinal studies. Test stimuli were selected to minimize differential item functioning based on gender or ethnicity. Demands for reading are minimzed.
Factor analytic studies have demonstrated that the test may be measuring a single factor rather than separate indices for both children and adults(e.g., Nelson et al., 2007) and while the Verbal and Composite Indices show good convergent validity with other measures of intellectual functioning, the Nonverbal Index did not perform well in terms of convergence validity or as a separate factor in factor analyses (Krach, S.K. et al., 2009; Nelson and Canivez, 2012)
Specific to Mitochondrial Disease:
Advantages: This measure was developed to minimize motor coordination and visual-motor speed demands, and thus is particularly useful in inidivuals with mitochondrial disorder who may present with muscle weakness or dyscoordination.
Administration: Items are administered orally or presented in stimuli books. The examinee generally provides a brief, phrase length or shorter response for verbal items and a point and/or brief verbal response for nonverbal items.
Age: 3 to 94 years old
Time: 20-25 minutes; 10 minutes for optional memory scales
Verbal Intelligence Index, Nonverbal Intelligence Index, Composite Intelligence Index, and an optional Composite Memory Index. Items are presented from a stimulus book or verbally and testees provide a brief verbal response or a point to indicate their response.
The RIAS intellectual scales are comprised of 4 subtests. Two verbal subtests (Guess What and Verbal Reasoning) comprise the Verbal Intelligence Index, and are designed to assess crystalized intelligence. Two nonverbal subtests (Odd Item Out and What's Missing) comprise the Nonverbal Intelligence Index and are considered measures of fluid intelligence. Raw scores for each of the subtests are converted to T-Scores. These T-scores are then summed and converted to generate Verbal and Nonverbal Index T-scores. VIX and NIX T-scores are summed and converted to a Composite Intelligence (CIX).
Two additional optional tests assessing short term memory can also be converted and summed as above to generate a Composite Memory Index.


Dombrowski, S.C., Watkins, M.W., Brogan, M.J. (2009) An Exploratory Investigation of the Factor Structure of the Reynolds Intellectual Assessment Scales (RIAS). Journal of Psychoeducational Assessment 27( 6): 494-507


Krach; K.S., Loe, S.A., Jones, W.P., and Farrally, A. (2009). Convergent Validity of the Reynolds Intellectual Assessment Scales (RIAS) Using the Woodcock–Johnson Tests of Cognitive Ability, Third Edition (WJ-III) With University Students. Journal of Psychoeducational Assessment 27 (5): 355-365


Nelson, J.M., and Canivez, G.L., Examination of the Structural, Convergent, and Incremental Validity of the Reynolds Intellectual Assessment Scales (RIAS) With a Clinical Sample. Psychological Assessment 24(1): 129-140.


Nelson, J.M., Canivez,G.L., Lindstrom, W. and Hatt, C. (2007). Higher-order exploratory factor analysis of the Reynolds Intellectual Assessment Scales with a referred sample. Journal of School Psychology 45: 439–456