Find and read a peer-reviewed research journal article using intelligence or achievement testing in research and share what you learned from this article with your classmates. Specifically (and in your own words):
1. Why was the study conducted? What hypotheses were being tested?
2. What test(s) were used?
3. What findings were reported, and what conclusions were drawn
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Why was the study conducted?,
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What hypotheses were being tested?,
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What test(s) were used?,
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What findings were reported?,
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What conclusions were drawn?
Comprehensive answers (in my own words)
Why was the study conducted? / What hypotheses were being tested?
The authors wanted to know whether intelligence tests currently used in German-speaking countries actually predict later school performance (school grades). They noted a gap in longitudinal evidence for several contemporary tests and therefore examined whether a child’s general intelligence score (measured at ~9 years old) would positively predict averaged school grades and grades in mathematics and language three years later. Their hypothesis was that the general intelligence indices would show positive (medium to strong) predictive associations with averaged school grades and with subject grades (mathematics and language). Frontiers
What test(s) were used?
The researchers administered four widely used intelligence tests (German versions): the Intelligence and Development Scales (IDS), the Reynolds Intellectual Assessment Scales (RIAS), the Snijders–Oomen Nonverbal Intelligence Test Revised 6–40 (SON-R 6-40), and the Wechsler Intelligence Scale for Children — Fourth Edition (WISC-IV). They used the general intelligence index from each test as the predictor. Baseline testing was done on 103 children; longitudinal school grade data (averaged, math, language) were collected about three years later for 54 children. Frontiers
What findings were reported?
When predicting averaged school grades three years later, the general intelligence indices from all four tests showed significant predictive validity. Looking at subject-specific grades, the IDS and the RIAS significantly predicted both mathematics and language grades; the SON-R 6-40 significantly predicted mathematics grades only; and the WISC-IV did not show significant associations with mathematics or language separately. The authors also reported that their sample had somewhat higher-than-norm intelligence means and that the follow-up sample was smaller (high dropout), which limits power and generalizability. Frontiers
What conclusions were drawn?
The study concluded that the general intelligence indices of these contemporary tests do predict later averaged school grades—supporting their predictive validity in psychological practice—while noting important caveats. Because of the small longitudinal sample and the fact that school grades can reflect noncognitive factors (motivation, self-control, teacher effects), the authors described the results as preliminary and recommended larger follow-up studies (and use of standardized achievement measures) to strengthen conclusions. They also suggested that practitioners can reasonably use these tests for predicting overall scholastic performance, but should be cautious about over-interpreting subject-specific forecasts and should consider noncognitive influences. Frontiers
What I learned / key takeaways (practical perspective)
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General intelligence scores remain useful predictors of later overall school achievement, but predictive strength can vary by test and by whether you look at averaged grades versus subject-specific scores. That means clinicians and educators can reasonably include a general IQ index when estimating overall scholastic prospects—but should avoid treating single test indices as definitive forecasts for a particular subject. Frontiers
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Test choice matters. Different instruments (IDS, RIAS, SON-R, WISC-IV) showed somewhat different patterns for subject prediction; nonverbal measures like the SON-R may predict math better than language, for example. Practitioners should match the test’s strengths to the decision at hand. Frontiers
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Context and limitations are crucial. Small samples, range restriction, and the fact that grades incorporate motivation and classroom factors mean test results must be integrated with other evidence (achievement tests, teacher reports, noncognitive measures) before making high-stakes decisions. Frontiers
Citation (APA style)
Gygi, J. T., Hagmann-von Arx, P., Schweizer, F., & Grob, A. (2017). The predictive validity of four intelligence tests for school grades: A small sample longitudinal study. Frontiers in Psychology, 8, Article 375. https://doi.org/10.3389/fpsyg.2017.00375 Frontiers