Anki is an incredibly powerful tool with a heap of learning science behind it.

But do you ever feel, as an Anki user, that the process is all a bit of a mystery? That, instead of being passively fed material, you might like to glimpse inside the flashcard box and find out a little more about its electronic, spaced-repetition plans for you?

A chance question from a teacher and polyglot pal this week helped open up that box for me. And it’s worth sharing this little-known secret with anyone who want a bit more data than the all-knowing app is ordinarily willing to provide.

Streak test for gold

It all starts with a streak. A learning streak, that is: a golden motivational corridor in educational gamification.

Streak is the presentation of unbroken, habitual use of the app as an achievement. And it has long been a staple of gamified platforms like Duolingo, which quickly grew on its sticky back. The streak almost becomes an end in itself, powering the language learning along with it. Proud players share their incredible feats with others who hope to reach the same heights.

On the face of it, streak does seem like an intuitively natural thing to want to know as a learner. How committed am I, in terms of how regularly I study? So it comes across as an odd omission from the standard Anki installation.

It all came to light when language buddy Marcel (so often a source of tips on everything language learning) asked if I knew where to find streak reporting in Anki. Despite the raft of data in the app’s familiar stats section, streak was nowhere to be seen. I was stumped.

Fortunately, a natty little plugin came to the rescue.

Review Heatmap

Review Heatmap adds a panel of information to the summary screens in the desktop version of Anki. Although the extra information seems quite standard, you might otherwise rack your brains to locate it in vain in a vanilla installation.

Although still in Beta for the latest 2.1.x stream of Anki releases (with a version for older versions here), it runs reliably and instantly exposes useful stats on the very first run.

Learning how you learn

Along with streak info, you can see a couple of other handy stats that do not feature in Anki’s regular data breakdown, including your average cards-per-day rate. And knowing about your learning is valuable meta-knowledge that can be just as useful as first-level learning material like vocabulary lists.

For example, take a look at the mass of colour in the plug-in display. Each square represents a day of your Anki year. You see the blanks? Those are the days on which you broke your streak. Interrogating the data like this can really help in the quest to learn how you learn.

Is there a pattern to them? Do they happen regularly? And can you use that information to preempt interruptions to your learning, and avoid them in future? In my case, hovering over my streak break blanks confirms what I suspected – they were days when family were visiting. Now I know this, I can try in future to review my Anki decks well in advance when I know I will have people round.

Streaks are not just about fun and pride. They encapsulate knowledge about your learning. And knowledge is power.

Pick a card, Anki card

The power of streaks is only one great way that Review Heatmap can boost your Anki learning. Like many things that just work, the app can be something of a black box. We adds words, Anki feeds them back to us using its clever algorithms. But sometimes, it can be informative to get a grasp on the workings inside that machine.

Exploring the heat map of coloured squares – the visual display style that gives the plug-in its name – can give you a more instinctive feel for how Anki schedules its cards. The darker the colour, the more cards scheduled on that day. By casting an eye over that annual map, you get a sense of the ebb and flow of card reviews, past and future. Hovering over individual squares even yields the exact number of reviews due on that day.

Not only that, but it is oddly satisfying to flick forward to subsequent years, and see reviews getting more and more infrequent. That gradual thinning out of card reviews is something special: it is Anki’s algorithm determining that you have, in accordance with the theory behind the system, memorised those words good and proper.

Obviously, numbers shift and change if you are actively adding cards all the time. But the visual snapshot is a fascinating way to start understanding how the spaced repetition approach plays out in real time.

Obviously, it also doesn’t hurt that Review Heatmap looks pretty funky in your Anki app. And there are some gorgeous colour options in the settings, too!

Turn up the heat

If you are ready to turn up the heat on your Anki routine by adding streak info and more, Review Heatmap is an essential add-on. Although it only boosts the desktop program, rather than the mobile apps, its insights can give you a real bird’s eye view over your learning.

As always with plug-ins, be sure to back up your Anki data before giving it a whirl.