After one school year, the dental-treatment class led in nine of ten psychological and psycho-physical tests, having led in only five of ten before treatment¶

Claim · All claims
Evidence · 1 study · causal r1 · q2
Currency · newest study 1913 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? After dental treatment, the treated fifth-grade class (Room 21) led the untreated comparison class (Room 18) in nine of ten tests, whereas before treatment Room 21 led in five of ten. → Emma Kohnky 1913

Evidence¶

Emma Kohnky 1913¶

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

q2 · i? · causal · r1

Conclusions-section tabulation summarizing which class showed net superiority on ten tests before and after dental treatment in a two-class controlled comparison. The author reports "finishing with a total of nine out of a possible ten" for the treated class. Medians are reported; no effect sizes or significance tests are printed.

"In all, then, Room 18 led five times out of a possible ten when the tests were given first, so that its ability would seem to be equal with that of the treated class. After dental treatment of its competitor, Room 18 leads but once, while Room 21 maintains its previous lead in five tests and gains the lead in four of the five remaining tests, finishing with a total of nine out of a possible ten."

Discussion¶

Related Claims¶

• The two fifth-grade classes were equivalent at baseline: Room 18 led on half of the ten non-physical tests before treatment — reports the opposite
• On the cancellation test the untreated class led before and after treatment, an exception attributed to the time limit — related
• Physical measures showed no appreciable difference in height and a larger weight gain in the untreated class — related
• On the seven-digit rote memory test the treated class gained 10.8% over its own first record while the untreated class gained none — related
• On the substitution learning test the treated class showed a larger saving of time (101.0 vs. 91.1 seconds) between first and last sheets — related
• The treated class showed greater gains in tapping endurance, leading in endurance on both hands by the second test despite greater initial fatigue — related