Tools for Thought

Last week I wrote about my recent experiences using the spaced repetition flashcard applications Mnemosyne. It’s now the only program I use for learning whatever material I want to maintain long term, but for almost a decade, my main tool for spaced repetition was SuperMemo for Palm OS, which was one of the first applications I used regularly on the Palm III.

I discussed the Palm version of SuperMemo briefly in the Mnemosyne post, but I wanted to cover it in more detail here, despite no longer using it regularly, for a few reasons.

• Many people find using a flashcard program on a PDA or smartphone more convenient or “natural” than a desktop app, natural in the sense of sharing the same portability of a physical deck of flashcards.
• The handheld version has a more streamlined interface than its desktop counterpart, making it an easier initiation into the spaced repetition paradigm.
• Portable versions may be more convenient for just-in-time learning on the street. For instance, if you’ve learned some basic French, but would like to retain whatever new phrases you come across on your trip to France, you can accrue a database of new expressions by entering them the moment you first encounter them.
• SuperMemo for Palm is now in a 2.0 version, and I wanted to see if there was any substantial improvement.

Spaced repetition

For those who haven’t read the Mnemosyne review, spaced repetition is an pattern of rote memorization where each item, or flashcard, is individually graded by the learner, then automatically scheduled for rehearsal based on an interval determined algorithmically, based on an exponential forgetting curve uncovered by memory research. Each card is set to be reviewed at the moment the curve would indicate that the learner will start to forget the item.

If a card is completely unlearned and graded “F,” it’s scheduled for review the next day. If a card is remembered easily and graded “A,” it might be scheduled to be seen again about a week later. The more times a card scores highly, the wider the interval of rehearsal, to the point where it might not by reviewed again for well over a year (decades would probably have to go by before I’d forget that “¿Cómo esta ustéd?” means “How are you?” in Spanish).

Since cards are scheduled for review on different days due to being individually graded, only a portion of any one database (deck) will be reviewed each day. On day three of memorizing the periodic table, for instance, you may only have to review 17 elements. This small load makes it compelling to continually add more material to SuperMemo each day, and suddenly the idea of learning two or three dozen new items or more each day is par for the course.

The Palm version

There are two ways to review databases in SuperMemo: as a drill and as a test. A drill is the mode where you review the entire deck and commit it to memory for the first time, answering each question/answer pair Right or Wrong. The drill continues until you answer all cards Right. You can run a drill for any database whenever you want.

A test is the mode that uses spaced repetition. It runs through all cards in a database the first time to record your A through F grade for each item, then uses those grades to determine which subset of cards you’ll see again on which day. At the end of the test mode, any items graded C or lower get put into drill mode, so you can run those poorly remembered items until you can answer them all correctly by the end of the session.

SuperMemo’s main screen shows the list of databases you’ve added, with either an asterisk or double rectancle icon at the left margin of each database name. An double rectangle denotes a database that’s been committed for test mode, an asterisk denotes a database that hasn’t been. Until you “commit” a database, you can only run it as a drill. Once you commit it, you review its contents on a sequence and schedule determined by SuperMemo, not you. It may be a day or two before you’re exposed to the cards for the first time as a test, though you can and should drill them first.

Each database can be categorized so that you can have, for instance, a Bible study database with each book (Genesis, Luke, etc.) as their own modules, though the whole databases is still tested as a single unit. Mnemosyne, on the other hand, has no separate categories, and by default is configured to test all databases in the same session; so Tagalog, US history and oceanography get mixed into one sitting if you have those databases entered.

Though SuperMemo separates each database, it’s still recommended that you run them all anyway if any items in each database are scheduled. The app shows you how many items in each deck are scheduled to the right of the deck’s name.

Entering cards from the desktop

Entering new items infrequently as they’re encountered, like collecting French phrases in France, is fairly convenient on Palm devices with qwerty keyboards. For batch entry it’s far less tedious to create database from the desktop. SuperMemo uses a small Windows utility called smconv.exe, creating a desktop icon into which you drag and drop an appropriately formatted text or tab delimited file. This creates a .pdb file that gets integrated into SuperMemo, merging with an older version of the database if it exists. The various formatting options are too involved to get into here but you for a text file with straightforward Q/A pairs, an example would look like:

Q: What is the atomic number of titanium?
A: 22

Q: What is the atomic weight of titanium?
A: 47.867

Questions and answers are separated by a newline, and each pair is separated by a double newline. For a tab delimited file, the first and second columns constitute the questions and answers, and each row is a pair. Formatting for entering supplementary information, like phonetic spelling, is detailed here.

Is SuperMemo for Palm worth learning for learning?

If your source material is primarily text based, then the Palm version of SuperMemo is vastly superior to a flashcard system that doesn’t use spaced repetition. If you have the discipline to complete your review sessions daily, it’s possible to increase the number of items you commit to long-term memory well beyond what you would be able to do with a standard flashcard deck. You don’t waste time reviewing cards you already know well, and you get extra reinforcement on the cards you don’t.

But you do have to be willing to review the cards on SuperMemo’s schedule. You may be anxious to review certain cards in less than the number of days slated. Though counterintuitive, intellectually this makes sense: the cards that people want to review tend to be the ones they remember well; the ones they grade poorly are the ones queued earlier. If you’d rather review all of your cards in a session, you can use SuperMemo’s drill mode, but drills don’t affect the testing schedule. Any items skipped on a certain day get piled onto the next session, so try to maintain a daily regimen.

Alternately, you can use the freeware flashcard app Learn?!, which sequences but doesn’t schedule cards in a grade-dependent queue. You review all the cards in each sitting, and any card answered five times correctly gets dropped out of the deck. Learning to use Learn?! is easier at the beginning that SuperMemo, but it’s hard to memorize anywhere near the same volume of material without repetition spacing.

If your source material is audio or graphical, you’ll either need to use the Pocket PC or desktop version, or another app like Mnemosyne or OpenCards. Links to these are found in the Mnemosyne review.

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