The counting days treatment's benefit for exam scores is mediated almost entirely by the number of days practiced, not the number of questions¶

Claim · All claims
Evidence · 1 study (2 entries) · causal r2 · q2
Currency · newest study 2025 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q3 i? GSEM mediation analysis shows the treatment's impact on exam scores was mediated by days of practice; the number of questions practiced had no significant effect on final exam score. → Iman YeckehZaare & Paul Resnick 2025 q3 i? Spacing practice over more days reduced the correlation between prior GPA and exam scores in the GSEM analysis. → Iman YeckehZaare & Paul Resnick 2025 (2)

Evidence¶

Iman YeckehZaare & Paul Resnick 2025¶

Iman YeckehZaare & Paul Resnick. (2025). Counting days is a spacing incentive that unlocks the potential of low GPA students. npj Science of Learning 10:35. https://doi.org/10.1038/s41539-025-00322-5

q2 · i? · causal · r2

GSEM mediation analysis of the within-class experiment (n = 143) with controls for gender, ethnicity, academic level, and native language. The printed path coefficient for practice days on exam scores is b = 0.088, controlling for total questions; no significant question-count effect was found.

"More days of practice increased exam scores ( b)a n d decreased the correlation between GPA and exam scores (e). We do not observe any significant effect of the number of questions practiced on the final exam score ( h)o ri t s interaction effect on the correlation of GPA and final exam score ( g)."

Iman YeckehZaare & Paul Resnick 2025 (2)¶

Iman YeckehZaare & Paul Resnick. (2025). Counting days is a spacing incentive that unlocks the potential of low GPA students. npj Science of Learning 10:35. https://doi.org/10.1038/s41539-025-00322-5

q2 · i? · causal · r2

Same GSEM analysis: among students with the same GPA and total questions, spacing practice over more days was associated with higher exam scores (b = 0.088) and with "a reduc t i o ni nt h ec o r r e l a t i o no f p r i o rG P A with exam scores (e = −0.024)". Findings are associational within the randomized design.

"Thus, the positive coefficient b = 0.088 implies that, for a pool of students with the same GPA who answered the same total number of questions, spacing out that practice over more days was associated with higher exam scores. Similarly, spacing out practice over more days was associated with a reduc t i o ni nt h ec o r r e l a t i o no f p r i o rG P A with exam scores (e = −0.024)."

Discussion¶

Related Claims¶

• A counting days grading incentive raises final exam scores more than a per-question points incentive in an introductory programming course — related
• Counting days incentive strongly increases the number of days of practice in both a within-class and a between-instructor experiment — related
• The spacing incentive benefits lower-GPA students more, nearly equalizing exam performance across prior GPA levels — related
• Counting questions students procrastinate, practicing little until late in the semester, while counting days spreads practice across the term — related