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Introduction
This test was designed by FunEducation, Inc. around 1998. It was refined
slightly by William McConochie, Ph.D., a psychologist
who works in partnership with FunEducation. Primarily,
Dr. McConochie's contribution is the scoring system,
statistical analysis and manual write-up. The test was
designed as a brief intelligence test for
administration over the Internet.
The test consists of 42 items in four content areas:
Quantitative, Spatial, Words and Fill in the Blank.
Three of the four content areas are "verbal", one
"spatial".
Basic Statistical Properties
The test was administered to 90,000 persons over the
Internet over several years. Initial norming was based
on smaller samples. Detailed statistical properties
were computed in September of 2007 for 65,000 of the
90,000 (the smaller size dictated by computer disk
storage limits).
This sample included 44 percent males, 56 percent
females. Scores for males and females were generally
equal. The greatest difference was a slight advantage
for males in the 12 spatial test items (.15**),
consistent with other research that shows a slight
advantage for males in this area of intelligence. The
total score advantage for males was also significant
but slight (.09**). Therefore, separate norms for
males and females are not used.
Norms are based on each age year from ages 7 through
29 and for 10 or 5-year age clusters thereafter. Mean
total raw scores rose in a steady arc from 22.4 for
7-year-olds to 28.7 for 25-year-olds and then remained
level through age 60. They gradually declined
thereafter to 24.0 for folks 85 and up.
Reliability Data
The Kuder-Richardson-21 reliability coefficients for a
sample of ages are as follow:
Age Sample size KR-21 reliability coefficient
10 297 .78
20 2270 .74
30 1696 .72
40 1111 .78
50 750 .76
60 286 .78
70 63 .84
80 23 .87
90 16 .96
Thus, the test has modest reliability. Longer tests
have higher reliability. For example, the Kids Verbal
I.Q. test and the Spatial I.Q. Test authored by Dr.
McConochie and normed over the Internet via
FunEducation.com both have approximately 200 items
over 5 test sections and have total score
reliabilities of .95. Thus, persons can take the
Free IQ Test for an initial estimate of their
intelligence and one or both of the two longer tests
for more reliable and more detailed scores.
Validity
The test is assumed to have content validity because
the item content is typical of intelligence test
content and the section scores all correlate in
typical fashion with each other, with the total score
and with other variables as expected:
Total I.Q. Quantitative Spatial Word Fill in Blank
Age Education Gender (+ = male)
Total 1.00 .81** .82** .74** .81** .08** .19** .09**
Quant .81** 1.00 .53** .44** .56** .14** .19** .08**
Spatial .82** .53** 1.00 .46** .57** .00 .14** .15**
Word .74** .44** .46** 1.00 .47** .06** .11** .01*
Fill in .81** .56** .57** .47** 1.00 .05** .15** .07**
Age .08** .14** .00 .06** .05** 1.00 .35** .09**
Ed .19** .19** .14** .11** .15** .35** 1.00 -.07**
Gender .09** .08** .15** .01* .07** 0.09** -.07** 1.00
Summary
The Free IQ Test is a brief modestly reliable
measure of general intelligence normed on large
samples of persons from age 7 to 90. It provides an
Internet product to introduce persons to intelligence
testing.
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