Yerkes-Bridges coefficients of intelligence of 1.20 or more are attained by very different percentages of children at successive ages (34.5% at ages 4-5 down to 0% at ages 16-17 and 18-on), so they do not represent the same degree of brightness at all ages.¶

Claim · All claims
Evidence · 1 study · theoretical r3 · q2
Currency · newest study 1917 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? The percentage of children attaining a coefficient of 1.20 or more falls irregularly from 34.5% at ages 4-5 to 0% at ages 16-17 and 18-on, so the coefficients are not comparable measures of brightness across ages. → ARTHUK S. OTIS (Stanford University) 1917

Evidence¶

ARTHUK S. OTIS (Stanford University) 1917¶

ARTHUK S. OTIS (Stanford University). (1917). A Criticism of the Yerkes-Bridges Point Scale, with Alternative Suggestions. The Journal of Educational Psychology, Vol. VIII, No. 3. https://eric.ed.gov/?q=Otis+criticism+Yerkes-Bridges+point+scale

q2 · i? · theoretical · r3

The article reports, citing the Yerkes and Wood article's Table III, that a "coefficient" of 1.20 or more is attained by the listed percentages of the normal group (total of 1282 individuals), concluding the coefficients "do not represent the same degree of brightness for the different ages." A secondhand analysis of reported percentages.

"a "coefficient" of 1.20 or more is attained by percentages of children of ages 4-5, 6-7, 8-9, 10-11, 12-13, 14-15, 16-17, 18-on, respectively, as follows: 34.5%, 33.0%, 15.8%, 13.7%, 5.5%, 6.5%, 0%, 0%"

Discussion¶

Related Claims¶

• Arbitrarily assigned point values in the Yerkes-Bridges scale yield implausible growth-rate results, such as intellectual ability increasing more than fifty per cent during the fourth year and only approximately fifteen per cent during the seventh. — related
• IQs obtained by dividing mental by chronological age remain fairly constant up to the age of 14, which supports treating yearly increments of intelligence as equal absolute units up to about age 14. — related
• In the Yerkes-Bridges alteration of the Binet Scale, equal point increments are assigned to digit-span steps whose growth intervals, as placed in the Binet Scale, are approximately 1, 3, 3, and 4 years. — related
• The probable error of a score on the language error tests is 2.24 — related
• The Yerkes-Bridges Point Scale scoring method fails entirely to accomplish its stated purpose of bringing out the full value of the test material. — related
• IQ is only approximately constant across successive examinations, with first-to-fifth IQ correlation of +0.82 and prediction error of 4 to 7 points — related
• Psychological studies of children's endowments show schools must set different aims and materials for different classes of children, and have broken up lock-step promotion — related
• The Binet-Simon and Yerkes Point Scale ratings of children run parallel and are practically identical up to age ten — related
• Most referred children in the sample rated below their chronological age on both scales — related
• Per cent solved is a variable, not a constant unit of difficulty, and is not comparable across groups — a broader claim this one bears on
• Scaling is a sine qua non for experimental use of tests, and unscaled tests interpreted as scaled do harm — a broader claim this one bears on