How are the RIAS and RIAS-2 Tests Scored?
The RIAS and RIAS-2 include a two-subtest Verbal Intelligence Index (VIX), a two-subtest Nonverbal Intelligence Index (NIX), and a Composite Intelligence Index (CIX), created by combining the VIX and NIX scores. The CIX assesses overall general intelligence (g), including the ability to reason, solve problems, and learn. A Composite Memory Index (CMX) is derived from the two supplementary memory subtests, Verbal Memory and Nonverbal Memory.
Although labeled the Verbal Intelligence Index, the VIX also is a reasonable approximation of crystallized intelligence. The NIX comprises subtests that assess nonverbal reasoning and spatial ability. Although labeled the Nonverbal Intelligence Index, the NIX also provides a reasonable approximation of fluid intelligence. These two indexes of intellectual functioning are then combined to form an overall Composite Intelligence Index (CIX). By combining the VIX and the NIX to form the CIX, a stronger, more reliable assessment of general intelligence (g) is obtained. The CIX measures the two most important aspects of general intelligence according to recent theories and research findings: reasoning or fluid abilities and verbal or crystallized abilities. Each of these indexes is expressed as an age-corrected student. These scores are normally distributed and can be converted to a variety of other metrics if desired.
The RIAS includes four subtests: Verbal Intelligence (VIX), Nonverbal Intelligence (NIX), Composite Intelligence Index (CIX), and the Composite Memory Index (CMX).
Each of the four RIAS subtests generates a raw score, which is the total number of correct responses given by the test-taker. These raw scores are then converted into standardized scores using age-based normative data, creating a more meaningful and interpretable measure.
For the VIX, NIX, and CMX, the standard scores have a mean of 100 and a standard deviation of 15. This means that a score of 100 is considered average, falling directly in the middle of the standard distribution of scores. A standard deviation of 15 implies that about 68% of scores will fall within one standard deviation of the mean (between 85 and 115), and about 95% of scores will fall within two standard deviations (between 70 and 130).
The CIX is an overall measure of intelligence derived from the VIX and NIX subtests and has a mean of 100 and a standard deviation of 15 as well.
Interpreting the Scores
Scores are generally interpreted as follows:
- Below 70: Extremely Low
- 70–79: Borderline
- 80–89: Low Average
- 90–109: Average
- 110–119: High Average
- 120–129: Superior
- 130 and above: Very Superior
Here’s a closer look at each subtest and what they measure:
- Verbal Intelligence (VIX): This subtest assesses verbal reasoning and concept formation skills, often linked to academic success. A high VIX score would indicate strong verbal reasoning abilities, whereas a low score might suggest difficulties in understanding or using verbal information.
- Nonverbal Intelligence (NIX): This measures nonverbal reasoning and spatial processing abilities, often associated with problem-solving skills and understanding complex concepts. A high NIX score suggests an individual is skilled in nonverbal problem-solving and concept formation, while a low score might indicate difficulty with these skills.
- Composite Intelligence Index (CIX): This is a combined measure of the VIX and NIX subtests, offering an overall estimate of a person’s intellectual capacity. It considers both verbal and nonverbal intelligence, thus providing a balanced picture of cognitive abilities.
- Composite Memory Index (CMX): This assesses an individual’s ability to remember verbal and nonverbal information after a delay. A high CMX score indicates good memory skills, while a low score may suggest memory difficulties.
When interpreting these scores, it’s essential to consider them within the broader context of the individual’s life, including their academic performance, socio-cultural background, and any known physical, psychological, or learning-related factors. It’s also important to remember that the RIAS, like all psychological assessments, is only one aspect of a comprehensive evaluation and should not be used in isolation to make diagnoses or decisions about interventions or supports.
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