Statistics of Letters

© December 2015 Paul Cooijmans


Scores on Letters

Contents type: Verbal.   Period: 2003-present

12 *
29 **
30 *
34 *
35 **
36 **
38 **
39 *****
40 ******

Correlation of Letters with other tests by Paul Cooijmans

(Test index) Test name n r
(41) The LAW - Letters And Words190.98
(44) Associative LIMIT40.98
(29) Words190.95
(30) Verbal section of The Marathon Test40.91
(40) Reason Behind Multiple-Choice - Revision 200870.84
(43) Test For Genius - Revision 201050.83
(68) Numbers40.80
(26) Verbal section of Test For Genius - Revision 200490.72
(3) Qoymans Multiple-Choice #570.70
(0) Test of the Beheaded Man40.69
(16) Lieshout International Mesospheric Intelligence Test50.64
(35) Intelligence Quantifier by assessment70.59
(1) Cartoons of Shock60.58
(24) Reason - Revision 200870.56
(66) Test For Genius - Revision 200440.53
(7) The Final Test60.48
(23) Gliaweb Riddled Intelligence Test - Revision 201160.48
(18) The Nemesis Test50.47
(19) Numerical section of Test For Genius - Revision 201050.46
(2) Cooijmans Intelligence Test - Form 360.44
(11) Isis Test70.44
(25) The Sargasso Test50.43
(28) The Test To End All Tests70.42
(10) Genius Association Test90.38
(39) Combined Numerical and Spatial sections of Test For Genius - Revision 201050.37
(27) Spatial section of Test For Genius - Revision 200480.29
(103) Problems In Gentle Slopes of the second degree40.18
(4) A Paranoiac's Torture: Intelligence Test Utilizing Diabolic Exactitude4-0.12
(80) Qoymans Multiple-Choice #44-0.13
(106) Cooijmans Intelligence Test - Form 44-0.35
(79) Association subtest of Long Test For Genius5-0.51

Weighted average of correlations: 0.562

Conservatively estimated minimum g loading: 0.75

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 Letters with tests by others

(Test index) Test name n r
(242) Unknown and miscellaneous tests70.54
(234) Strict Logic Sequences Exam I40.03
(246) Sequentia Numerica Form I4-0.34

Weighted average of correlations: 0.170

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 Letters 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 Letters on that type

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

Balanced g loading = 0.72

National medians for Letters

Country n median score

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 Letters

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

Correlation of Letters with personal details

Personalia n r
Gifted Adult's Inventory of Aspergerisms70.89
P.S.I.A. Aspergoid70.65
P.S.I.A. Deviance factor100.61
P.S.I.A. Rational70.50
P.S.I.A. Introverted70.45
P.S.I.A. Neurotic70.37
P.S.I.A. Extreme70.34
P.S.I.A. System factor60.34
Educational level210.24
P.S.I.A. Rare70.21
Observed associative horizon30.16
P.S.I.A. Orderly70.15
Disorders (parents and siblings)210.11
P.S.I.A. Ethics factor100.10
P.S.I.A. Cold70.10
P.S.I.A. True70.08
P.S.I.A. Just70.01
Year of birth22-0.10
P.S.I.A. Cruel7-0.18
Disorders (own)21-0.33
Father's educational level19-0.34
Mother's educational level20-0.48
Candidate's self-estimated I.Q.5-0.50
P.S.I.A. Antisocial7-0.70

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.

Raw scoreUpward g (n)Downward g (n)
00.75 (201)NaN (0)
120.75 (201)NaN (0)
200.64 (167)NaN (0)
290.64 (167)NaN (0)
300.46 (123)NaN (0)
320.42 (113)NaN (0)
340.42 (113)0.92 (4)
350.41 (112)0.97 (12)
360.38 (109)0.95 (17)
370.39 (94)0.95 (17)
380.39 (94)0.76 (73)
390.17 (34)0.75 (149)
40NaN (0)0.75 (201)



Scores by age

Age class n median score
50 to 54234.0
45 to 49339.0
40 to 44234.0
35 to 39239.5
30 to 34140.0
25 to 29436.5
22 to 24140.0
20 or 21438.0

Scores by year taken

Year taken n median score

ryear taken × median score = 0.15 (n = 22)

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.

The items of this test perform well in item analysis, which is also expressed in the very high reliability of the test.