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.¶

Claim · All claims
Evidence · 1 study · theoretical r2 · q2
Currency · newest study 1917 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? Point-scale-derived growth rates (more than fifty per cent in the fourth year, scarcely more than thirty in the fifth, approximately fifteen in the seventh) indicate an erroneous scale construction rather than genuine growth. → 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 · r2

The article reports, quoting Yerkes and Wood (p. 604), these yearly increases in point-scale-measured ability. Otis attributes the pattern to giving one point to each of too many small increments in the easy part of the scale, calling the authors' interpretation an unwarranted confidence in arbitrarily assigned points. Secondhand reported data, analyzed critically.

"During the fourth year of life, intellectual ability (always understood as measured by the point scale) increases more than fifty per cent.; during the fifth year of life, by scarcely more than thirty per cent.; during the seventh year, by approximately fifteen per cent."

Discussion¶

Related Claims¶

• 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. — a narrower finding that bears on this claim
• 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
• 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. — related
• The Binet-Simon and Yerkes Point Scale ratings of children run parallel and are practically identical up to age ten — related
• Per cent solved is a variable, not a constant unit of difficulty, and is not comparable across groups — related
• 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