Cooijmans Intelligence Test - Form 1 Statistics

The norms ("G" = raw score):

G  Protonorm
48 173
49 180
50 187
51 193
52 200
53 207
54 213
55 220
56 227
57 223
58 240
59 247
60 253
61 260
62 267
63 273
64 280
65 287
66 293
67 300
68 307
69 313
70 320
71 327
72 359
73 361
74 367
75 377
76 378
77 379
78 380
79 381
80 382
81 383
82 385
83 386
84 388
85 389
86 393
87 413
88 427
89 433
90 447
91 459
92 461
93 467
94 478
95 479
96 481
97 482
98 487
99 500
100 507
101 520
102 547
103 553
104 559
105 560
106 561
107 567
108 580
109 593
110 606
111 608
112 613
113 620
114 627
115 633
116 640
117 647
118 653
119 667
120 680
121 693
122 707
123 720
124 740
125 760
126 780
127 807
128 833

• Quality of norms: 0.76

The scores

# testees: 60
Mean: 90.6
SD: 12.44
Male mean: 90.5
Female mean: 98 (1 persons)

60*
69*
71*
72*
74*
75**
77***
78*
79***
81**
82*
84*
86***
87*****
89*
90****
91**
92*
93**
94***
95**
96*
97*
98**
99**
101*
102**
103*
104*
106*
107*
108*
110*
113*
114*
118**

Correlation with other tests

Norming

Used for norming are the prior tests correlating .6 and higher. Prior scores are converted to an IQ scale with a standard deviation of 15. Prior and raw scores are rank-equated, missing scores are interpolated and there is a bit of extrapolation above and below.

The test appears to be harder than it seemed before, judging by the overall higher norms. Also remarkable is that only one female has taken it so far. Considering my observation about male and female ratios and score differences in the report "Correlations between Cooijmans tests", this too indicates the test is very hard.

To improve internal consistency, 25 items are removed from the test. Most of those are too easy, some have too low correlations with total score. The remaining 39 items, CIT Form 2, have correlations with total score (in the CIT Form 1) from .26 to .61, and difficulties (percentage of testees missing the item) from 7 to 95.

Additional statistics March 2008

Scores

• # candidates: 65
• Median: 90.0
• Quartile deviation: 9.5
• Range: 66
• Maximum possible: 128
• Mean: 89.2
• Standard deviation: 13.89
• Male mean: 89.0
• Female mean: 98.0 (# females: 1)
• Hardness: 0.30
• Resolution: 0.58

Correlation with other tests

Weighted average of correlations: 0.409

Conservatively estimated minimum g loading: 0.64

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 5 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.

National averages

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

Correlation with personal details

Correlation with national IQs

Correlation of this test with national average IQs published by Lynn and Vanhanen:

• r = 0.27
• n = 56

Reliability and standard error

Using the "split-half" method:

• Rel = 0.87
• SE = 5.1 raw score points

Scores by age

Scores by year taken

Correlation year taken vs average score = -0.84
n = 63

Robustness and overall test quality

• Rob = 1.00
• Quality = 0.73