We can only take in so many bits: input stream limitations.
Chunking can increase intake. (associations to other things and prior knowledge)
Review increases retention because the information becomes more integrated into the environment which memory reflects.
Memory mirrors the environment: so the frequency and recency(i.e. pattern of exposure) in the environment will be mapped to the memory. If it comes up frequently and recently then the memory will hold onto it, not forget it, and make it more accessible.
Take last 30 days, what would be the best pattern of exposure? Recency every other day 15 times each.
Every other day .5368
Pack it in up front then occasionally review .4975
Every 3 days .543
First five days then last 5 days .5137
First day then a week later then 5 days later then 5 days later then 4 then 3 then 2 then 1 after that .558