srf - spaced repetition flashcards

I have been using srf to study Mandarin for about 6 months now, with a selection of decks imported from anki, and cards I have created myself. 

My study time is better regulated and I am making better progress than when I was studying with anki. 

The difference is the scheduling algorithm. The scheduler in srf regulates new cards automatically, to maintain a target study time per day and sorts due cards differently, allowing good progress even with a large backlog of due cards (e.g. after not studying for a few days).

Initial development of srf is now complete. Rate of change is slowed. The user interface, particularly for editing content, remains a bit crude but adequate. Lately, I spend most of my time studying and very little developing the program.

I was reluctant to develop a new program. It took a lot of time away from study. But the limitations of the anki scheduler were too frustrating and it is now clear that a better scheduler makes a big difference to progress. From a technical perspective, the differences are subtle and simple but practically they make a big difference.

The essential differences are:

• present cards with shorter interval before cards with longer interval
• automatically regulate new cards based on past and future workload

Presenting cards with shorter intervals first makes a big difference when working through a backlog. Anki presents cards in the order they were due, regardless of interval. The difference is subtle but important.

With a large backlog in Anki, the backlog effectively blocks review of cards with shorter intervals. Unfamiliar / difficult cards are not seen as soon as they should be, defeating learning. With a large enough backlog, it is practically impossible to learn: one churns through a large number of cards without making progress because it is too long between reviews.

The problem is exacerbated by anki introducing more new cards every day, despite the backlog. It is possible to change the number of new cards per day manually but paying attention to this takes attention away from studying.

The scheduler in srf prioritizes the cards you are learning (with shorter intervals) over the backlogged cards. Thus, one can learn despite the backlog and that learning is the way to clear the backlog. And while there is an excessive backlog, srf does not introduce new cards, so gradually, reliably, the backlog is cleared. When it is cleared, new cards are introduced again.

With these changes, study time per day is more consistent: varying closely around configured target study time per day. And progress is better when one is not overloaded.