I am conducting a study on delayed post-testing under different acquisition methods, grounded in Ebbinghaus’s forgetting curve. Currently, there is no standardized timing for delayed post-tests in academic research. However, most studies focus on immediate post-tests, three-day, and seven-day intervals, with some exploring longer delays. My previous study employed immediate, three-day, and seven-day post-tests. Still, the differences in development trends across different experimental groups were not very distinct.

In this experiment, I plan to examine memory trend variations between the experimental and control groups across different acquisition methods, with testing intervals set for the same day, 7 days, 14 days, and 30 days. I have the following questions:

• Under these circumstances, how many delayed post-tests would be most reasonable?
• Is there any specific theoretical basis or literature to support the selection of these timing intervals?

Thank you for any advice!