Today I read an amazing article in Wired about Piotr Wozniak, the inventor of software that uses spaced repetition to help you learn things permanently. Spaced repetition is where you learn something, then relearn it right at the point where you’re about to forget it. Each time you relearn it, you remember it for a longer period of time. The concept is simple, but requires a computer to determine the exact point at which you need to relearn something.
Wozniak created software called SuperMemo (SM) to implement the spaced repetition algorithm. In essence, it’s the ultimate flashcard program. It allows you to use images, HTML, and sounds, too. His latest feature is “incremental reading”, where you grab a bunch of documents from the web (or email, etc.) and throw them into SM. You prioritize the documents as you insert them; when you have time to read them, SM determines the order. As you read the document, you pull out info nuggets that you don’t want to forget, and these get added to the flashcard stack. Interesting, but it sounds like a bit of work.
Although it can be used to learn anything, the killer app is language learning. Indeed, in Wozniak’s native Poland, SuperMemo has been used extensively by students of English who wish to study abroad. There’s also rampant piracy and use in China and other countries. However, piracy is unnecessary, since Wozniak writes openly about the algorithms he uses, and open source alternatives have arisen.
One standout is Mnemosyne. It also offers support for HTML, images, and sound. One interesting feature is the 3-sided flashcard, which is particularly suited to language learning by including written form, pronunciation, and translation.
Another free program I saw recommended was OpenCards. It is based on OpenOffice Impress, a free PowerPoint alternative. As such, your flashcards can contain anything that can go into a PowerPoint slide, such as background images, animation, video, sound, etc. OpenCards runs on all major operating systems.
One issue I had with this super learning system is that, other than language, I couldn’t think of much that I wanted to keep in permanent memory. It did occur that in addition to foreign words, this is a great way to retain a large English vocabulary and keep it sharp. In On Writing, Stephen King recommends expanding your vocabulary by reading good authors and looking up words you don’t know. I already do this, but now I can retain them indefinitely. That’s pretty cool.
If I was in school, however, this would be a fantastic way to retain knowledge for tests. I did a lot of cramming, which they tell you not to do. Cramming helps you pass quizzes and tests that cover recent lessons, but when it comes to the comprehensive final, it fails. High school students who use this system diligently can demolish memorization-heavy AP tests. Not to mention the vocabulary-heavy SAT. Heck, this could make even high school language courses worthwhile! And all of this would lead to a clear advantage in college, where the same system should also work wonders. Later in life, you can brag about graduating magna cum laude - in French! - even though you studied something you never ended up using.
Update/Clarifications (4/23/08)
In case I didn’t sell this strong enough, the Wired article explains how cognitive psychologists and memory researchers are completely baffled as to why everyone isn’t using this technique. They equate it to using torches when light bulbs are available.
Although there is an obvious use for high school students, it occurred to me that placement in accelerated classes starts as early as 3rd grade. In my school system, you had to be placed there by 7th grade if you wanted to take the most advanced math classes in high school. So parents probably should start their kids as early as 2nd grade.
You don’t need to leave your computer on all the time - it will save your progress to disk 
However, it is important to use the software daily. Skipping several days can set you back quite a ways.
Another free program is Anki. While it’s a general purpose spaced rep. program, it has extra features for learning Japanese, English, and Russian. Students of Japanese can also try Reviewing the Kanji. It was also suggested in the Lifehacker forums that Pimsleur language CDs (which are available at your local library) could be converted to OpenCards decks for optimal aural learning.
