A vote against spaced repetition

ancientcampus

LessWrong seems to be a big fan of spaced-repetition flashcard programs like Anki, Supermemo, or Mnemosyne. I used to be. After using them religiously for 3 years in medical school, I now categorically advise against using them for large volumes of memorization.

[A caveat before people get upset: I think they appropriate in certain situations, and I have not tried to use them to learn a language, which seems its most popular use. More at the bottom.]

A bit more history: I and 30 other students tried using Mnemosyne (and some used Anki) for multiple tests. At my school, we have a test approximately every 3 weeks, and each test covers about 75 pages of high-density outline-format notes. Many stopped after 5 or so such tests, citing that they simply did not get enough returns from their time. I stuck with it longer and used them more than anyone else, using them for 3 years.

Incidentally, I failed my first year and had to repeat.

By the end of that third year (and studying for my Step 1 boards, a several-month process), I lost faith in spaced-repetition cards as an effective tool for my memorization demands. I later met with a learning-skills specialist, who felt the same way, and had better reasons than my intuition/trial-and-error:

Flashcards are less useful to learning the “big picture”
Specifically, if you are memorizing a large amount of information, there is often a hierarchy, organization, etc that can make leaning the whole thing easier, and you loose the constant visual reminder of the larger context when using flashcards.
Flashcards do not take advantage of spatial, mapping, or visual memory, all of which the human mind is much better optimized for. It is not so well built to memorize pairs between seemingly arbitrary concepts with few to no intuitive links. My preferred methods are, in essence, hacks that use your visual and spatial memory rather than rote.

Here are examples of the typical kind of things I memorize every day and have found flashcards to be surprisingly worthless for:

The definition of Sjögren's syndrome
The contraindications of Metronidazole
The significance of a rise in serum αFP

Here is what I now use in place of flashcards:

Ven diagrams/etc, to compare and contrast similar lists. (This is more specific to medical school, when you learn subtly different diseases.)
Mnemonic pictures. I have used this myself for years to great effect, and later learned it was taught by my study-skills expert, though I'm surprised I haven't found them formally named and taught anywhere else. The basic concept is to make a large picture, where each detail on the picture corresponds to a detail you want to memorize.
Memory palaces. I recently learned how to properly use these, and I'm a true believer. When I only had the general idea to “pair things you want to memorize with places in your room” I found it worthless, but after I was taught a lot of do's and don'ts, they're now my favorite way to memorize any list of 5+ items. If there's enough demand on LW I can write up a summary.

Spaced repetition is still good for knowledge you need to retrieve immediately, when a 2-second delay would make it useless. I would still consider spaced-repetition to memorize some of the more rarely-used notes on the treble and bass clef, if I ever decide to learn to sight-read music properly. I make no comment on it's usefulness to learn a foreign language, as I haven't tried it, but if I were to pick one up I personally would start with a rosetta-stone-esque program.

Your mileage may vary, but after seeing so many people try and reject them, I figured it was enough data to share. Mnemonic pictures and memory palaces are slightly time consuming when you're learning them. However, if someone has the motivation and discipline to make a stack of flashcards and study them every day indefinitely, then I believe learning and using those skills is a far better use of time.

[A caveat before people get upset: I think they appropriate in certain situations, and I have not tried to use them to learn a language, which seems its most popular use. More at the bottom.]

Incidentally, I failed my first year and had to repeat.

Flashcards are less useful to learning the “big picture”
Specifically, if you are memorizing a large amount of information, there is often a hierarchy, organization, etc that can make leaning the whole thing easier, and you loose the constant visual reminder of the larger context when using flashcards.
Flashcards do not take advantage of spatial, mapping, or visual memory, all of which the human mind is much better optimized for. It is not so well built to memorize pairs between seemingly arbitrary concepts with few to no intuitive links. My preferred methods are, in essence, hacks that use your visual and spatial memory rather than rote.

Here are examples of the typical kind of things I memorize every day and have found flashcards to be surprisingly worthless for:

The definition of Sjögren's syndrome
The contraindications of Metronidazole
The significance of a rise in serum αFP

Here is what I now use in place of flashcards:

Ven diagrams/etc, to compare and contrast similar lists. (This is more specific to medical school, when you learn subtly different diseases.)
Mnemonic pictures. I have used this myself for years to great effect, and later learned it was taught by my study-skills expert, though I'm surprised I haven't found them formally named and taught anywhere else. The basic concept is to make a large picture, where each detail on the picture corresponds to a detail you want to memorize.
Memory palaces. I recently learned how to properly use these, and I'm a true believer. When I only had the general idea to “pair things you want to memorize with places in your room” I found it worthless, but after I was taught a lot of do's and don'ts, they're now my favorite way to memorize any list of 5+ items. If there's enough demand on LW I can write up a summary.

For what it's worth: Though I do not claim to be a perfect user of SRS flashcards, I used them intensively for 3 years of medical school, constantly refining my technique. Many people here have suggested ways to improve my strategies. I have not yet seen an idea that I have not already tried extensively. Though I'm far from perfect, I think it's safe to say I have a better understanding than most beginners. There certainly is room for me to improve, but not much. If someone is considering using SRS long term for high volumes in medical school, here is my advice: it is possible a Perfect SRS User could use it more effectively than I did, but if you haven't already used SRS for years, you aren't such a person.

I never read that article, but I figured out many of those on my own. I agree with many of them, disagree with some. My input, for those that use it:

-Cloze deletion is simple, but to me, it is far too easy to "guess the teacher's password" using that technique, and is of limited use. It's great for high-school level fact regurgitation, but less useful for post-graduate stuff. You will quickly become good at the deck, but it does not strongly help your understanding of the material. That's an important point: your skill at answering questions in the deck does not necessarily translate to your skill at answering questions in real life.

-Graphic deletion - I used to do this all the time, but it is really time consuming to set up. I consider myself fast with an image-editor, but it's still a big drain. (Again, this is more of an issue in high volume) It also runs into the Cloze deletion problem.

-Use imagery: heck yes. I highly agree, in any situation (flashcards or no)

-Any technique splitting a larger whole into many smaller flashcards (the article lists several): This is possibly the WORST suggestion for high volume. While this is certainly very useful, again, when you use it in high volume I have found mental fatigue to become an issue. If you don't include the entire whole, you miss out on the big picture in a situation where the big picture truly is important. If you DO include the whole, you run into the cloze deletion "guessing the teacher's password" problem. That said, it has its uses in smaller volume, but I will never again use it in a high-volume deck.

To give an example: As the article suggests, I used to take a diagram, set up graphic deletion (make a series of images where a single element was blotted out), and run through the cards.

1) this takes a lot of startup time

2) Even ignoring the time to make the cards, I found reviewing the cards to be more time consuming than simply looking at the diagram, covering up the lables, and attempting to recall.

3) You get no practice recalling the diagram from memory

4) This technique is most effective if you will later see that exact diagram in real life/on the test, I argue it is a pitfall for guessing the teacher's password and provides less intuitive understanding of the diagram.

The strength in SRS comes from not wasting time on the easy parts and only spending time on the hard parts of the diagram. The theory is, after the first two cycles, you're only reviewing the "hard" parts of the diagram. On the other hand, you've spent more time making the cards, more time for the first and second card cycles, you're taking a big hit to the "big picture" style, and have no practice conjuring the diagram itself from memory. Ignoring the big picture and general understanding elements: if SRS provides any time benefit for the rote memorization vs going without SRS cards, i would only expect the benefit to "catch up" in 3 weeks BARE minimum; for me (for fatigue reasons in high volume) I pin the crossing point at 3 to 6 months, assuming it's an unintuitive diagram I use infrequently enough that I will forget it without review. I also argue that it provides a weaker general understanding of the diagram as a whole.

Just to comment on the last bit: It seems odd to me that you stress the "3 weeks BARE minimum" and the "crossing point at 3 to 6 months" as a con, while you have used SRS for three years. Given that SRS is used for retention, and assuming that 6 months is the "crossing point", one would think that after three years of consistent SRS use you'd reap a very nice yield.

I know it's a metaphoric language, but it seems additionally ironic that the "BARE minimum" you stress equals to your frequency of exams, while you disfav... (read more)