What is a good algorithm for spaced review?

Question

I made a wall calendar outlining study tasks to complete over a 2-year period. Each day, there are 3 new tasks (each coming from 1 of 3 textbooks). Each day, I'll progress through the activities in the textbooks at a rate of 1 chapter per week.

I'd like to add some dates for review of all of these tasks. E.g., Task 1 falls on day 1, 2, 4, 8, 16, etc. Task 2 falls on day 2, 3, 5, 9, 17, etc.

• Are there any algorithms based on research that I could use that use to assign an ideal date for each review?
• How can I adjust the algorithm such that I do not have too many reviews in the same day?

Answer 1

I think you're on the same path with Piotr Wozniak! Please read his story here:

Want to Remember Everything You'll Ever Learn? Surrender to This Algorithm

He is the inventor of the SM2 algorithm used in SuperMemo and it gave insight to many other similar applications such as Anki and Mnemosyne. That algorithm might give you some insight. Spaced repetition is a very interesting topic. You may check Vic Spilzman's answer on my question here. He perfectly explains the significant parts. The Wired article given above has many discussions on scientific research related to spaced repetition such as the work of Ebbinghaus, Bjorks and Wozniak.

I had tried a similar way as you but it was difficult to handle. First, you need to have 'units of information' if you want to rely on related research. Chapters hold lots of information of which you remember some parts very well during repetition whereas you don't remember anything of the remaining and it becomes difficult to classify your level of remembering to use in the algorithm. You should divide the information into smaller chunks so that you can review more often the part that you forget quickly. Secondly, software helps a lot!

What I do now is to create flashcards on Anki from the materials I read, i.e. the chapters are formed into small units of information held on flashcards. Then I leave the rest to the algorithm on the software. There are some info that I still need to review often since I can't remember it correctly :) whereas some are simpler and the software does not waste my time by showing them again and again when I say it is simple during review. When I need to edit the flashcard, I mark it during review and modify afterwards.

To sum up:

• SM2 might give you insight under the terms I told (i.e. divide and conquer)
• You need to modify the next review time according to your level of retention. I recommend to use a software (such as Anki) for this. It will limit elapsed time or maximum items per day for you.