Maintaining Your Collection

Ah, maintenance. It might not be fun, but to paraphrase Brian Foote and Joseph Yoder, if you think doing maintenance isn’t fun, try not doing maintenance.

Exactly what kind of maintenance you should do on your spaced-repetition collection depends on how, and how much, you use spaced repetition, and the guidelines provided below should not be taken as rules the violation of which will void your Anki Warranty. The guidelines do suggest a program for avoiding buildups of inefficient learning and bad cards that aligns with my experience using Anki over many years, but I would be lying if I claimed I had always, or even usually, done everything as laid out here!

Once a day

• Edit or mark any cards you find that are wrong or imprecise.
• Delete or suspend any cards you don’t think are worth studying anymore. (If your distaste includes a whole category of material, you might prefer to mark the card and review the category later.)
• Make notes of any new material you need to add. For instance, you might notice that you’re struggling to differentiate two items, or one of your cards uses a term that you’re unfamiliar with.

The main daily task in spaced repetition study, and by far the most important, is of course to review your due cards. But while you’re doing so, be on the lookout for issues! Some problems with the structure of your cards are much more visible while reviewing, and it’s all too easy to be lazy and return flawed cards to review over and over, wasting your time.

If you’re sitting down to do many reviews, consider keeping a notecard and a pencil next to you in case you spot something that needs significant additional work. This way, there’s much less effort associated with fixing something: make a note so you don’t forget (without having to get up), then fix the problem or put it on your to-do list once you’re done.

Once a week

• Fix the cards that you’ve marked as problematic during review. (In Anki, search for tag:marked in the browser.)
• Decide how to deal with any leeches that your SRS has flagged and suspended. (In Anki, search for tag:leech.)

Marked cards and leeches are better taken care of sooner rather than later, while you still have some memory of what the issue with the card was. However, doing this work every day on just a card or two at a time may be too much to ask. Once a week has always felt like a reasonable compromise to me.

Once a month

• In Anki, check your database, delete any empty cards, and delete unused media. These built-in checks will ensure that cruft doesn’t build up in your collection. You can find the options near the top of the Tools menu in the desktop version; on AnkiMobile, look in the preferences screen.
• Look for cards that have been added recently and have already accumulated more than a couple of lapses. This might make you go “Oh yeah, I’ve been having trouble with that one,” and point out gaps in your understanding or cards you could stand to rewrite, without having to wait until the card is identified as an obvious leech. A handy search for this in Anki is added:60 prop:lapses>2. (Adjust the number of days ago to consider a “recently added” card and the number of lapses to taste. Presses of Again while the card is still in learning mode aren’t considered “lapses”; a lapse happens only when the card enters review mode successfully, indicating that you’ve learned it, but you then forget it again.)
• Make sure your collection is backed up! Losing a mature collection with tens of thousands of cards is a catastrophe. Syncing with AnkiWeb is a great first step, even (or especially) if you only use Anki on one device. The service is free and doesn’t steal your data, track your movements around the web, or show you ads, so there’s not a whole lot of reason not to use it unless you keep incredibly sensitive information in your collection. And you do have a backup of your whole computer, right? Be sure it includes your Anki data folder.

Twice a year

• Review whether your organizational structure is still serving your needs.
• As you do that, review whether you still care about all the content within that structure (see bullet point four in the link). You can either suspend or delete this information. If you suspend it, you can choose to relearn it later, or treat it as reference material you can search for. But if you simply don’t care anymore and don’t expect you ever will again, you should just delete it. (A good idea in that case is to export it to an apkg file before deleting and keep the file in a backups folder somewhere – then if you realize you made a mistake, you can always import it back. If nothing else, this will make you more comfortable about deleting it!)
• In Anki, scan through your list of note types and merge any that are essentially the same or that are no longer used; if you import lots of shared decks, you can quickly end up with extras. (Choose Tools -> Manage Note Types. If you don’t know much about note types, now is a great time to learn.)
• On the desktop version of Anki, check that your add-ons are up-to-date and disable any that you don’t use anymore. Add-ons are great, but add-ons you’re not using just expose you to more software bugs without giving you anything in return. (Visit Tools -> Add-ons for these options.)