Updated 7.12.2011.

What is SRS?

SRS stands for “Spaced Repetition System”, and works off the idea that you should stretch out the time in which you review whatever it is that you’re studying in order to keep it in long term memory. That’s the short answer, anyway.

I first heard about SRS over at AJATT (All Japanese All The Time) in a number of his blogs. And I’ve got to say, it’s working damned well for me. One thing Khatz stresses is that drilling yourself repeatedly to try and remember something only utilizes your short term memory, and therefore it stays there – in short term memory.

Take, for example, that kid in your class in high school or college that always aced his exams by cramming the night before. Ask him about any of it a week later: さようなら, it was gone. Great for the short term, completely useless for trying to learn and retain anything.

SRS works off the concept of “spacing” out your reviews. For example, say you have 2 kanji you’re trying to remember. One of them you could easily recall in your mind, accurately. Why keep reviewing on that particular one, when there are others which are more challenging to review? The other kanji you struggle with, so you need to see it more often (for now, at least).

Most SRS programs have some sort of system in place where you rate yourself on how well you remembered it. Furthermore, each time you remember an item correctly, it’s next review time is pushed out further. So, a typical review schedule might look something like this (listed by number of times correct):

  1. Next review in 3 days
  2. 7 days
  3. 14 days
  4. 30 days
  5. 60 days
  6. 120 days
  7. 240 days

By the 7th review, it’s engrained in your long-term memory (most likely was way before then, actually, but definitely by 7th). The idea is that once it’s there, let it be for a bit, and try to recall it a bit later down the road. If it was easy, the program might even push it out further. Reviewing material in this manner places the content in your long term memory.

Now, you might ask, what about those I struggle with? Most SRS programs will place the kanji (or whatever) back in the first review if you get it wrong – essentially starting over. This is okay. It will help reenforce that particular kanji in your mind. Once you start getting it correct, it’s review is once again pushed out further each time.

At first, you won’t be reviewing very often (maybe once every other day) until your kanji numbers start adding up. Pretty soon, you’ll have more than enough to review every day. As such, one thing should be kept in mind – you don’t have to necessarily review everything that is due that day, but it should be done within a few days of that date so you don’t fall behind. I’ve found the crossed-out text above not to be as efficient as reviewing all cards that are due on the day that they are due. More about this here.

So far, this sounds like a lot to keep track of. It is. Sure, you could write out everything on index cards, keep them in separate piles and mark it on your calendar… OR you could use an SRS program to handle that part of it for you. After all, you’ve got enough on your plate studying. With that, there are several programs out there to do this:

  • Reviewing the Kanji – for the kanji portion, hands down the best tool out there. It’s geared toward Heisig’s book (RTK1), and matches with frame numbers, etc. The cards already exist, you just have to tell it which ones you want to add to your review deck as you move through the book. Free. Web-based. Update: I no longer use this because I find Anki easier to work with cross-platform. It’s just more convenient in my opinion.
  • SuperMemo – I haven’t used it myself, but I’ve heard awesome things about it. Good for use during, but mostly after the kanji stage. NOT free ($50 last time I checked).
  • Anki – Another solid choice for an SRS. Like above, but free. Update: This is what I’m currently using.
  • Mnemosyne – Another free SRS alternative.
  • SuRuSu – A free SRS developed by the owner of All Japanese All The Time. Web-based.
  • All of these and more are also listed on the links and tools pages.

In the end, it doesn’t really matter which one you use, as long as you actually use one. Every day.