A forgetting-curve graph has two axes. The bottom axis is time, in days after learning. The side axis is how much you remember, from nothing at the bottom to everything at the top.
- The solid line shows memory with reviews. Each jump up is a review: you recall it again and memory returns to the top.
- After each jump the line falls more slowly than the time before.
- The dashed line shows memory with no reviews: it drops and stays low.
Worked example: Worked example
On the graph above, about how much is remembered just before the first review, compared with just before the day-21 review?
- Find the dip just before day 1: the line is low, near the middle.
- Find the dip just before day 21: the line has fallen only a little from the top.
Answer: Less before day 1; much more before day 21, because each review slowed the fall.
Key idea
A steeper drop means faster forgetting. A flatter line means the memory is getting stronger.
Common mistake
Reading the exact numbers off an illustrative curve. These pictures show a shape. Use them to compare, not to predict a score.