multiple copies of lossy compressions with different level of resolutions
Hell Fast·
Explanations prompt you to connect each idea back to what you already know
These extra connections—called elaborations—act like multiple retrieval cues, making recall easier.
actively solving problems makes it much easier to remember
you have to retrieve relevant facts or procedures from memory rather than simply re-read them. That act of retrieval strengthens the memory trace, making it easier to recall later.
还有 Space out practice 还有 emotion
Since resources are limited, choices have to be made:
What to produce (e.g., food, cars, technology).
How to produce it (e.g., labor-intensive vs. capital-intensive).
For whom to produce (e.g., distribution among people).