Kohnky 1913 two-class dental-treatment comparison design with a Whipple test battery and coin-toss assignment¶

Design · All designs
Evidence · 2 claims (2 for) · 1 study (1 causal), q2 · 0 of 1 report an effect size · 2 claims rest on one study

Description¶

This element is the study design of Kohnky's 1913 preliminary study: two fifth-grade classes in one down-town school, matched on grading, neighborhood, and foreign-birth composition, with the experimental class chosen "decided by the toss of a coin." The treated class received full dental care including "treatment, tooth-brush drills, dinners," while a nurse and social visitor monitored compliance. Outcome measures were Whipple's tapping, cancellation, memory-span, and substitution tests plus weight and height, administered in October and May by two experimenters. The untreated class "received only such attention as they sought, which was found to be practically none."

Design Implications¶

Context¶

Requirements¶

Tests must be given by the same experimenters at both testing occasions, as the article arranged
A non-treated comparison class must be available in the same school with like home and social conditions

Constraints¶

The author concedes the ongoing dental work itself introduced "the disturbing factor introduced by the actual carrying on of the dental work in the experimental class"
Only children present at both testings were counted
Results use medians rather than averages to neutralize extremes

Target Learners¶

elementary school children (fifth grade)

Learning Goals¶

physical and mental efficiency of school children

Claims¶

Examples¶

-

Key Sources¶

Emma Kohnky, M.A. (1913). Preliminary Study of the Effect of Dental Treatment upon the Physical and Mental Efficiency of School Children. The Journal of Educational Psychology. https://www.jstor.org/journal/jeducpsych

Page metadata

Field	Value
`type`	`design`
`id`	`kohnky-1913-dental-treatment-comparison-design`
`title`	`Kohnky 1913 two-class dental-treatment comparison design with a Whipple test battery and coin-toss assignment`
`description`	`This element is the study design of Kohnky's 1913 preliminary study: two fifth-grade classes in one down-town school, matched on grading, neighborhood, and foreign-birth composition, with the experimental class chosen...`
`status`	`review`
`generated`	by `process:settle-candidates` on `2026-10-25`
`trust`	unverified — no one has confirmed this page's content
`sources`	1 — `emma-kohnky-1913`

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