What is the causal impact of the mnemonic medium’s review sessions on reader retention?

Quantum Country readers reliably develop detailed retention for embedded questions, but that data is correlative. What’s the causal impact of a marginal session, at a particular time?

We’ve run a few studies on this question; see Quantum Country efficacy RCTs for more.

Some relevant results which demonstrate the counterfactual:

Last updated 2023-07-13.