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On Day 1, at the beginning of the lecture, you go in knowing nothing, or 0%, (where the curve starts at baseline).  At the end of the lecture you know 100% of what you know, however well you may know it (where the curve rises to at its highest point).

By Day 2, if you have done nothing with the information you learned in that lecture; did not think about it again, read it again, etc., you will have lost 50-80% of what you learned.  Our brains are constantly recording information on a temporary basis: scraps of conversation heard on the sidewalk, what the person in front of you is wearing, what we hear on the news.  Because this information is not necessary and it does not come up again, our brains dump it all off, along with what was learned in the lecture that you actually want to hold on to!

By Day 7, we remember even less and by Day 30, we retain about 2%-3% of the original hour!  This nicely coincides with midterm exams and may account for feeling as if you have never seen this before in your life when you are studying for the exams—you may need to actually re-learn it from scratch.

But wait!!! You can change the shape of the curve!

Reprocessing the same chunk of information sends a big signal to your brain to hold onto that data.  When the same thing is repeated, your brain says, “Oh, there it is again, I better keep that, it must be important.”  When you are exposed to the same information repeatedly, it takes less and less time to “activate” the information in your long term memory and it becomes easier for you to retrieve the information when you need it.

Here is formula and the case for making time to review your material:

  • Within 24 hours of getting the information—spend 10 minutes reviewing and you will raise the curve to almost 100% again.
  • A week later, (Day 7) it will only take 5-10 minutes to “reactivate” the same material and again raise the curve.
  • By Day 30, your brain will only need 2-4 minutes to give you the feedback to retrieve the information.

Often students feel they cannot possibly make time for a review session every day given their busy schedules—they have trouble keeping up as it is.  However, this review is an excellent investment of time.  If you do not review you will need to spend 40-50 minutes relearning each hour of material.  Do you have that kind of time?  Cramming rarely stores information in your long term memory successfully.  This will make it difficult to retrieve the information when you need it for a test.

Depending on the course load, the general recommendation is to spend half an hour every weekday and 1.5 to 2 hours every weekend in review activity.

Many students are amazed at the difference reviewing regularly makes in how much they understand and how well they understand and retain the material.  It is worth experimenting for a couple of weeks, just to see what difference it makes to you!

The Curve of Forgetting Graph:

The Curve of Forgetting describes how we retain or get rid of information we take in. It's based on a one-hour lecture.

Curve of Forgetting Graph