For schools, where the Difference derives from median indices, the middle 50 per cent of 56 tested schools fell within plus 3 to minus 3, making school differences beyond 3 significant¶

Claim · All claims
Evidence · 1 study · associational r2 · q2
Currency · newest study 1920 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? Among 56 different schools tested, the middle 50 per cent showed Differences from plus 3 to minus 3, so school difference values greater than minus 3 indicate attainment too far below capacity. → Pintner 1920

Evidence¶

Pintner 1920¶

Pintner, R., and Marshall, H. (1920). A Combined Mental-Educational Survey. The Journal of Educational Psychology. https://www.google.com/search?q=A+Combined+Mental-Educational+Survey+Pintner+Marshall

q2 · i? · associational · r2

School-level application of the Difference method: each school's Difference comes from the median mental and educational indices of all its children, which decreases the spread of difference values. No effect size is printed.

"In all, 56 different schools were tested and the middle 50 per cent show differences from plus 3 to minus 3. For schools or classes a difference of medians above or below 3 becomes significant."

Discussion¶

Related Claims¶

• A Difference score comparing educational and mental index values diagnoses whether a child's attainment is commensurate with measured ability, with Differences between minus 8 and plus 8 occurring in about half of cases — related
• Cases with Differences of minus 9 or below — 21.5 per cent of the standardization sample — are described as marked cases of wasted intelligence whose ability is not being utilized — related