Statistics of the Lieshout International Mesospheric Intelligence Test

Scores on Lieshout International Mesospheric Intelligence Test as of 27 August 2020

Contents type: Spatial.   Period: 2004-present

• n: 100
• Median: 18.0
• Quartile deviation: 2.8
• Range: 26
• Maximum possible: 30
• Male median: 18.0 (n = 96)
• Female median: 19.0 (n = 4)
• Resolution: 0.34

Correlation of Lieshout International Mesospheric Intelligence Test with other tests by I.Q. Tests for the High Range

Weighted average of correlations: 0.537 (N = 1251, weighted sum = 672.06)

Conservatively estimated minimum g loading: 0.73

Ranking in above table is based on the unrounded correlations. All available data is present in this table, no tests are left out except for those with less than 4 score pairs. All known pairs are used, including possible floor/ceiling scores or outliers.

Correlation of Lieshout International Mesospheric Intelligence Test with tests by others

Weighted average of correlations: 0.341 (N = 223, weighted sum = 75.99)

Ranking in above table is based on the unrounded correlations. All available data is present in this table, no tests are left out except for those with less than 4 score pairs. All known pairs are used, including possible floor/ceiling scores or outliers.

Please be aware that correlations with these external tests are in most cases affected (depressed, typically) by one or more of the following: (1) Little overlap with the object test because of the much lower ceilings and inherent ceiling effects of the tests used in regular psychology; (2) Candidates reporting scores selectively, for instance only the higher ones while withholding lower ones; (3) Candidates reporting, or having been reported by psychometricians, incorrect scores.

Estimated loadings of Lieshout International Mesospheric Intelligence Test on particular item types

These are estimated g factor loadings, but against homogeneous tests (containing only particular item types) as opposed to non-compound heterogeneous tests. Although tending to surprise the lay person, it is not uncommon for tests to have high loadings on item types they do not actually contain themselves. Such loadings reflect the empirical fact that most tests for mental abilities measure primarily g, regardless of their contents; that the major part of test score variance is caused by g, and only a minor part by factors germane to particular item types. It is of key importance to understand that this is a fact of nature, a natural phenomenon, and not something that was built into the tests by the test constructors.

N = 920

Compound tests have been left out of this table to avoid overlap.

Balanced g loading = 0.70

National medians for Lieshout International Mesospheric Intelligence Test

For reasons of privacy, only countries with 2 or more candidates are included in this table. Ranking is based on the medians, and then alphabetic.

Correlation with national I.Q.'s of Lieshout International Mesospheric Intelligence Test

Correlation of this test with national average I.Q.'s published by Lynn and Vanhanen:

• r = 0.11 (n = 100)

Correlation of Lieshout International Mesospheric Intelligence Test with personal details

Correlation with personal details of Lieshout International Mesospheric Intelligence Test - within females

Correlation with personal details of Lieshout International Mesospheric Intelligence Test - within males

Estimated g factor loadings upward and downward of particular scores

In parentheses the number of score pairs on which that estimated g factor loading is based. The goal of this is to verify the hypothesis that g becomes less important, accounts for a smaller proportion of the variance, at higher I.Q. levels. The mere fact of restricting the range like this also depresses the g loading compared to computing it over the test's full range, so it would be normal for both values to be lower than the test's full-range g loading.

Reliability

• Split-half (odd-even) = 0.80
• Split-half (other division) = 0.87
• Cronbach's alpha = 0.87

Remark: The reliability of this test (.87) is somewhat lower than what is striven for and achieved in most tests (.9 or greater). This is largely due to the relatively low number of problems in the test (30). This reliability in turn puts an upper limit on the correlations with any other variables, and hence on the test's g loading, which as a result is also somewhat lower than usual. These lower values are not problematic because it concerns a subtest, and not an I.Q. test in its own right. By combining the test with another test, the overall reliability becomes well over .9, and the combined g loading rises.

Error

• Standard error = 1.8 raw score points

Scores by age

N = 100

Scores by year taken

r_{year taken × median score} = -0.56 (N = 100)

Do notice the significant downward trend in raw scores on this test, both here and below under "Robustness". Also notice the difference between "year taken × median score" (which effectively has an n of 17 here because there are 17 years) and "raw scores × months" (n = 100 because there are 100 raw scores).

Robustness and overall test quality

• Robustness by chronological rank = 0.78
• Robustness by month = 0.79 (r_{raw scores × months} = -0.24)
• Quality = 0.709

Item analysis

Item statistics are not published as that would help future candidates. To detect bad items, answers and comments from candidates are studied, as well as, for each problem, the correlation with total score and the proportion of candidates getting it wrong (hardness of the item). Possible bad items are removed or revised, resulting in a revised version of the test. This test contains no items that are currently in need of revision.

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