Allowing ACT-R memory parameters to vary with the between-session interval produces a strong fit between model and recall data across timescales¶

Claim · All claims
Evidence · 1 study · associational r2 · q2
Currency · newest study 2026 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? Dividing learning sequences into interval bins and fitting model parameters separately per bin yields a strong correspondence between data and model, whichever parameter is varied. → Maarten van der Velde 2026

Evidence¶

Maarten van der Velde 2026¶

Maarten van der Velde, Florian Sense, Jelmer P. Borst & Hedderik van Rijn. (2026). Explaining forgetting at different timescales requires a time-variant forgetting function. npj Science of Learning. https://doi.org/10.1038/s41539-026-00447-1

q2 · i? · associational · r2

Model-fitting analysis in which data were split into bins of equal width on a logarithmic scale by between-session interval, with parameters fitted per bin. The article reports that "this procedure produces a strong correspondence between data and model, irrespective of which parameter we vary." No effect size is printed.

"As Figs.1d, 1f, and1h show, this procedure produces a strong correspondence between data and model, irrespective of which parameter we vary."

Discussion¶

Related Claims¶

• In 5-fold cross-validation, multi-bin time-variant model fits outperform single-bin fits, with diminishing returns beyond a 5-bin split and further gains from differentiating by learner and amount of practice — related
• Optimal ACT-R parameter values change systematically and predictably with the length of the between-session interval — a narrower finding that bears on this claim
• Extrapolating from parameters fitted to a restricted range of between-session intervals produces worse predictions than time-variant fits — a narrower finding that bears on this claim
• A single time-invariant ACT-R forgetting function cannot simultaneously capture recall accuracy on short and long between-session intervals — related