Statistics of Isis Test

© Paul Cooijmans

Scores on Isis Test as of 23 February 2023

Contents type: Verbal, numerical.   Period: 2001-present

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Correlation of Isis Test with other mental ability tests

Test name n r
KIT Intelligence Test - first attempts50.89
Short Test For Genius40.81
Labyrinthine LIMIT60.80
The Piper's Test120.79
A Relaxing Test40.79
International High IQ Society tests (aggregate)60.74
Gliaweb Riddled Intelligence Test (old version)50.72
The Nemesis Test300.70
The Marathon Test110.68
The Alchemist Test110.65
Cooijmans On-Line Test - Two-barrelled version130.63
Dicing with death90.62
Cooijmans Intelligence Test - Form 4160.62
Verbal section of The Marathon Test110.60
Narcissus' last stand180.57
Verbal section of Test For Genius - Revision 2016170.55
Spatial section of The Marathon Test160.54
Test For Genius - Revision 2004170.54
Numerical and spatial sections of The Marathon Test160.54
Reflections In Peroxide260.54
Reason Behind Multiple-Choice70.53
The Final Test - Revision 2013100.51
Numerical section of The Marathon Test160.50
The Hammer Of Test-Hungry - Revision 201390.49
Titan Test (Ronald K. Hoeflin)100.49
The Sargasso Test250.48
Problems In Gentle Slopes of the first degree120.47
Miscellaneous tests260.46
Genius Association Test240.46
Only idiots60.45
The Bonsai Test - Revision 2016200.44
Psychometrically Activated Grids Acerbate Neuroticism70.44
Test For Genius - Revision 2016170.43
Cooijmans Intelligence Test 5210.43
Test of the Beheaded Man180.43
A Paranoiac's Torture: Intelligence Test Utilizing Diabolic Exactitude250.42
The Test To End All Tests260.42
Psychometric Qrosswords100.41
Cartoons of Shock140.40
Lieshout International Mesospheric Intelligence Test250.38
Wechsler Adult Intelligence Scales80.37
Divine Psychometry60.36
Spatial section of Test For Genius - Revision 2004260.35
Associative LIMIT200.35
Gliaweb Riddled Intelligence Test - Revision 2011160.35
Bonsai Test80.34
Verbal section of Test For Genius - Revision 2004250.33
Problems In Gentle Slopes of the second degree190.30
Qoymans Multiple-Choice #5390.29
Tests by Mislav Predavec (aggregate)60.27
Problems In Gentle Slopes of the third degree150.26
Spatial Insight Test40.26
Cooijmans Intelligence Test - Form 290.25
Space, Time, and Hyperspace110.24
Reason Behind Multiple-Choice - Revision 2008380.22
Test For Genius - Revision 2010110.22
The Final Test130.21
Long Test For Genius90.21
Numerical section of Test For Genius - Revision 2010310.20
Combined Numerical and Spatial sections of Test For Genius - Revision 2016220.20
Analogies of Long Test For Genius100.18
Space, Time, and Hyperspace - Revision 2016230.17
The LAW - Letters And Words80.14
Epiq Tests (aggregate)60.13
Combined Numerical and Spatial sections of Test For Genius - Revision 2010140.12
Reason - Revision 2008380.10
Daedalus Test130.10
Cooijmans Intelligence Test - Form 3270.09
Strict Logic Sequences Exam I (Jonathan Wai)100.09
Logima Strictica 36 (Robert Lato)80.08
Qoymans Multiple-Choice #4160.07
Non-Verbal Cognitive Performance Examination (Xavier Jouve)6-0.02
Scholastic Aptitude Test (old)4-0.10
Association subtest of Long Test For Genius11-0.13
Strict Logic Spatial Exam 48 (Jonathan Wai)6-0.26

Weighted average of correlations: 0.368 (N = 1159)

Estimated g factor loading: 0.61

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.

The correlations with other tests are uncommonly low as a result of the limited variance of raw scores on this test.

Estimated loadings of Isis 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.

Typeng loading of Isis Test on that type

N = 872

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

Balanced g loading = 0.53

National means for Isis Test

Country n mean score

For reasons of privacy, only countries with 3 or more candidates are included in this table. Ranking is based on the unrounded means, and then alphabetic.

Correlation with national I.Q.'s of Isis Test

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

Correlation of Isis Test with personal details

Personalia n r
Observed associative horizon100.75
PSIA Rational - Revision 2007140.73
PSIA Ethics factor - Revision 2007140.50
PSIA True - Revision 2007140.47
PSIA Just - Revision 2007140.46
Observed behaviour220.37
PSIA System factor - Revision 2007140.37
PSIA Orderly - Revision 2007140.21
PSIA Cold - Revision 2007140.20
PSIA Introverted - Revision 2007140.17
PSIA Deviance factor - Revision 2007140.15
PSIA Extreme - Revision 2007140.14
PSIA Rare - Revision 2007140.09
Gifted Adult's Inventory of Aspergerisms200.05
PSIA Antisocial - Revision 2007140.04
Year of birth960.02
Mother's educational level790.00
PSIA Aspergoid - Revision 200714-0.01
Father's educational level76-0.02
Educational level84-0.06
Disorders (parents and siblings)83-0.17
Disorders (own)85-0.18
PSIA Neurotic - Revision 200714-0.18
PSIA Cruel - Revision 200714-0.40
Cooijmans Inventory of Neo-Marxist Attitudes9-0.68

Reliability and error

Due to the small number of items and limited variance in scores and item scores, it is not possible to compute reliability and error meaningfully for this test from its internal statistics. What can be said is that a test's reliability is necessarily higher than its g loading because reliability forms the upper limit of a test's possible correlations with any other variables.

Scores by age

Age class n Mean score
70 to 7410.00
65 to 6921.00
60 to 6420.00
55 to 5930.00
50 to 5460.00
45 to 4970.14
40 to 4460.50
35 to 39110.18
30 to 34110.09
25 to 29190.05
22 to 24110.45
20 or 2140.00
18 or 1990.22

N = 96

Scores by year taken

Year taken n mean score

ryear taken × mean score = 0.07 (N = 100)

Robustness and overall test quality

Item analysis

Item statistics are not published as that would help candidates. To detect bad items, answers and comments from candidates are studied, as well as, for each problem, the correlation with total score on the remaining problems (item-rest correlation) and the proportion of candidates getting it wrong (hardness of the item). Possible bad items are revised, replaced, or removed, possibly resulting in a revised version of the test.