Statistics of Isis Test

© October 2008 Paul Cooijmans

Norms

Scores

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1 **

Correlation with other tests

Test#cor
Numbers80.65
Titan Test30.61
The Nemesis Test70.55
Cartoons of Shock60.37
The Test To End All Tests70.34
The Final Test80.32
Scholastic Aptitude Test (old)30.03
Strict Logic Sequences Exam I40.00
The Sargasso Test5-0.01

Weighted average of correlations: 0.354

Conservatively estimated minimum g loading: 0.60

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 3 score pairs. All known pairs are used to obtain the true, honest statistics; Correlations are not artificially inflated by leaving out ceiling scores, outliers or other anomalies.

Additional statistics October 2014

© October 2014 Paul Cooijmans

Scores on Isis Test

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

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Correlation of Isis Test with other tests by Paul Cooijmans

(Test index) Test name n r
(56) Short Test For Genius40.81
(36) Reflections In Peroxide80.81
(48) Narcissus' last stand80.77
(103) Problems In Gentle Slopes of the second degree50.75
(18) The Nemesis Test160.72
(4) A Paranoiac's Torture: Intelligence Test Utilizing Diabolic Exactitude90.69
(68) Numbers110.66
(21) Psychometric Qrosswords40.65
(35) Intelligence Quantifier by assessment150.64
(0) Test of the Beheaded Man80.64
(31) Numerical section of The Marathon Test50.63
(82) Reason70.62
(69) Odds60.60
(66) Test For Genius - Revision 2004160.55
(62) Reason Behind Multiple-Choice70.53
(27) Spatial section of Test For Genius - Revision 2004200.53
(45) Numerical and spatial sections of The Marathon Test50.52
(42) The Marathon Test50.52
(3) Qoymans Multiple-Choice #5130.51
(15) Letters70.44
(26) Verbal section of Test For Genius - Revision 2004200.41
(30) Verbal section of The Marathon Test60.41
(1) Cartoons of Shock110.37
(32) Spatial section of The Marathon Test50.36
(2) Cooijmans Intelligence Test - Form 380.36
(41) The LAW - Letters And Words60.35
(84) Bonsai Test80.34
(40) Reason Behind Multiple-Choice - Revision 2008130.34
(5) Daedalus Test60.33
(28) The Test To End All Tests140.32
(10) Genius Association Test120.31
(29) Words60.29
(57) Space, Time, and Hyperspace100.28
(25) The Sargasso Test110.28
(55) Spatial Insight Test40.26
(87) Cooijmans Intelligence Test - Form 290.25
(16) Lieshout International Mesospheric Intelligence Test80.25
(63) Long Test For Genius90.21
(7) The Final Test120.21
(24) Reason - Revision 2008130.18
(44) Associative LIMIT70.15
(75) Analogies of Long Test For Genius90.14
(80) Qoymans Multiple-Choice #4150.06
(79) Association subtest of Long Test For Genius9-0.17

Weighted average of correlations: 0.417

Conservatively estimated minimum g loading: 0.65

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 to obtain the true, honest statistics; correlations have not been artificially inflated by leaving out ceiling scores, outliers or other anomalies.

Note: Considering that the test has only 5 items and that most scores are 0 and there is very little variance in scores, and that those circumstances tend to depress a test's correlations with other tests, a g loading of .65 is amazingly high.

Correlation of Isis Test with tests by others

(Test index) Test name n r
(239) Titan Test90.46
(225) Logima Strictica 3670.09
(234) Strict Logic Sequences Exam I60.08
(243) Scholastic Aptitude Test (old)4-0.10
(240) Strict Logic Spatial Exam 484-0.36

Weighted average of correlations: 0.114

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 to obtain the true, honest statistics; correlations have not been artificially inflated by leaving out ceiling scores, outliers or other anomalies.

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 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.

Typeg loading of Isis Test on that type
Verbal0.54
Numerical0.80
Spatial0.62
Logical0.58
Heterogeneous0.73

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

Balanced g loading = 0.65

National means for Isis Test

Country n mean score
Korea_South21.00
Canada20.50
United_States140.36
Australia20.00
Finland40.00
Greece40.00
Spain20.00
United_Kingdom30.00

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

Correlation of Isis Test with personal details

Personalia n r
P.S.I.A. System factor100.87
Observed associative horizon80.77
P.S.I.A. Cold160.77
P.S.I.A. Rational160.70
P.S.I.A. Just160.70
P.S.I.A. True160.45
Observed behaviour140.45
P.S.I.A. Ethics factor200.44
P.S.I.A. Aspergoid160.33
P.S.I.A. Introverted160.31
Year of birth480.30
P.S.I.A. Deviance factor200.27
P.S.I.A. Rare160.22
Mother's educational level370.16
Sex490.12
P.S.I.A. Neurotic160.07
P.S.I.A. Antisocial160.01
P.S.I.A. Cruel16-0.02
Gifted Adult's Inventory of Aspergerisms11-0.05
P.S.I.A. Extreme16-0.08
Educational level40-0.10
Father's educational level36-0.13
P.S.I.A. Orderly16-0.14
Disorders (parents and siblings)39-0.25
Disorders (own)39-0.27
Cooijmans Inventory of Neo-Marxist Attitudes4-0.85

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

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

Reliability

Note: The low reliability is caused by the very low number of items (5, while 30 is generally the minimum to have sufficient reliability) and by the fact that most scores are 0. There is therefore very little variance in the item scores (and that variance is the basis of the computation of reliability). This result is probably misleading and the real reliability likely much higher, as also implied by the test's g loading; reliability is necessarily higher than g loading as it puts an upper limit on a test's possible correlations with any other variables.

Error

Scores by age

Age class n median score
70 to 7410.0
55 to 5920.0
50 to 5450.0
45 to 4930.0
40 to 4430.0
35 to 3950.0
30 to 3440.0
25 to 29110.0
22 to 2460.0
20 or 2110.0
18 or 1940.0
1720.5
1411.0

Scores by year taken

Year taken n median score
200120.0
200250.0
200470.0
200540.0
200650.0
200720.0
200860.0
200960.5
201050.0
201220.0
201320.0
201431.0

ryear taken × median score = 0.50 (n = 49)

Robustness and overall test quality

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.