Counting days incentive strongly increases the number of days of practice in both a within-class and a between-instructor experiment¶

Claim · All claims
Evidence · 1 study (2 entries) · causal r2 · q2–q3
Currency · newest study 2025 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q3 i? In the within-class experiment, counting days students practiced on far more days (mean 38.5 vs. 17.3) than counting questions students. → Iman YeckehZaare & Paul Resnick 2025 q3 i? In the between-instructor experiment, counting days students averaged 17.4 practice days vs. 12.0, a statistically significant difference. → 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

q3 · i? · causal · r2

Within-class randomized experiment (n = 143): the counting days group "practiced on more than twice as many days on average (38.5 vs. 17.3)"; Table 2 prints a t-test statistic of 20.436*** (p < 0.001) for Practiced Days. No effect size is printed.

"the counting days group practiced on more than twice as many days on average (38.5 vs. 17.3), but only answered a few more total questions (415 vs. 392.5)."

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

Between-instructor randomized experiment: 71 instructors teaching 1,648 students were randomized at the instructor level; counting days students averaged 17.4 vs. 12.0 practice days. Table 5 reports t = 5.616*** (p < 0.001).

"Students in the counting days condition averaged 17.4 days of practice vs. 12.0 in the counting questions condition, as shown in Table 4."

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
• The counting days treatment's benefit for exam scores is mediated almost entirely by the number of days practiced, not the number of questions — 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
• Class climate—peer uptake and instructor credit incentives—relates to larger Exam Playbook effect sizes — related