The Three Per Cent. Hypothesis produced a distribution of children's home cases closer to the normal curve than the C. M. A. method, skewed left with most cases in the backward group¶

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

Subclaims¶

q2 i? Graph I shows the Three Per Cent. Hypothesis distribution of the home cases lies closer to the normal curve than the C. M. A. distribution, and is skewed to the left with the majority of cases in the backward group. → Pintner 1917

Evidence¶

Pintner 1917¶

Pintner, R. (1917). The Mentality of the Dependent Child, Together with a Plan for a Mental Survey of an Institution. The Journal of Educational Psychology. https://doi.org/10.1037/h0075825

q2 · i? · design · r2

Graphical comparison (Graph I) of the 106 home children's distributions under the two diagnostic methods. The author cautions the curves "prove nothing" but calls the differing distributions suggestive.

"It will be noted that the Three Per Cent. Hypothesis gives a curve much closer to the normal curve than the C. M. A. The cuive showing the distribution according to the Three Per Cent. Hypothesis is skewed to the left and the majority of the cases fall in the backward group."

Discussion¶

Related Claims¶

• In the unselected county children's home population, the C. M. A. standard yielded 20.8% feeble-minded while the Three Per Cent. Hypothesis yielded 5.7%, with most children classified backward — related
• Among 82 state charity cases of dependent children, the most conservative estimate put 19.5% feeble-minded and only about 37% testing up to normal — related