A problem's diagnostic value as a measure of general ability can be indexed by the slope of its pass-rate ogive at the 50% point¶

Claim · All claims
Evidence · 1 study · associational r1 · q2
Currency · newest study 1917 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? Plotting passes by rank-ordered ability groups yields ogive curves whose steepness at the 50% point indexes a problem's diagnostic value; Problem 8 of Arithmetic Test I appears best. → Arthur S. Otis 1917

Evidence¶

Arthur S. Otis 1917¶

Arthur S. Otis. (1917). An Absolute Point Scale for the Group Measurement of Intelligence.—Part II. The Journal of Educational Psychology. https://doi.org/10.1037/h0074753

q2 · i? · associational · r1

Graphical analysis (Fig. 5) of the 16 problems of Arithmetic Test I for 121 individuals ranked by total point score, with passes counted in overlapping groups of 30. The author reports "the diagnostic value of Problem 8 appears to be the best" and that, excepting Problems 6 and 7, diagnostic values seem satisfactory.

"The problems may now be ranked in diagnostic value according to the slope of the curve at the 50% point. Thus it will be seen that the diagnostic value of Problem 8 appears to be the best."

Discussion¶

Related Claims¶

• Per cent solved is a variable, not a constant unit of difficulty, and is not comparable across groups — related