That growing backlog is a big issue with this type of scheduling. I think it's one of those almost "unexpected" side-effects of spaced repetition. I mean, if you did the math up front, you should know generally how busy you're going to be over the next few weeks based on how many cards you're reviewing per day, how many new ones are coming, and how you're scoring with each card, but it's not really something people do, nor does the UI show you that.
I wrote my own spaced repetition app (see my profile) and one thing I experimented with is an "ETA" function which goes through your deck and tells you how long before you learn everything "well enough", where "well enough" just means the intervals between all cards is at least some fixed threshold, like one month. I was surprised that even with a few hundred cards and a fixed number of cards reviewed per day, it would still take a few months.
I haven't added the ETA feature yet, but if I do, I think I would need to make sure to show the user how adding new cards affects that target date, and also how reviewing more cards a day or fewer cards a day affects it. I think there's a way to design a nice UI so users feel like they are in control of that end date so they can choose if it's worth it to add new cards or not.
I think a spaced repetition app should also make "falling behind" not feel catastrophic. I think memorizing a smaller set of facts consistently is better than trying to memorize a larger set and then giving up, and an app's UI can probably help to that end.
> I think memorizing a smaller set of facts consistently is better
In general, existing SRS does a very bad job of supporting priority and prerequisites between items. There's no way of saying "learn A, B, C, then learn X, Y, Z once you know the former well enough." This limits the domains where SRS can be applied most effectively to ones with very little structure, such as raw language vocabulary.
> In general, existing SRS does a very bad job of supporting priority and prerequisites between items.
This is a feature I've wanted to implement for a while, but I think it would be hard from a user's perspective to set up the dependencies. Specifically, I mean marking a card unlearnable until another card (or cards) is learned. It's something that I think requires a good UI so you can see at a glance which cards depend on which other cards. You'd go in and essentially make a skill tree of all the cards. It might be something more useful for more serious deck creators.
My dream is being able to create a deck where you have both vocab and then sentences that use the vocab. You'd make sentences that use the vocab dependent on the vocab being learned first, so that over time you'd gradually unlock more material that uses your base knowledge.
>My dream is being able to create a deck where you have both vocab and then sentences that use the vocab. You'd make sentences that use the vocab dependent on the vocab being learned first, so that over time you'd gradually unlock more material that uses your base knowledge.
Pretty unnecessary in my experience. I only did around 2k sentences and that was for the express purpose of internalizing grammar, and found that 99 times out of 100 it was pretty natural to just learn the new vocab that came with the sentence. There would be the occasional one that would take a few times before I got it, but it was pretty insignificant problem.
After I smashed out all the grammar I just did purely vocab after that and it worked like an absolute charm.
> My dream is being able to create a deck where you have both vocab and then sentences that use the vocab. You'd make sentences that use the vocab dependent on the vocab being learned first, so that over time you'd gradually unlock more material that uses your base knowledge.
You can also go the other way. Have a huge database of sentences, and pick example sentences for new cards which only use vocabulary which you already know (besides the new word which you want to learn through that card, of course). I do that for my Japanese SRS app, and it works decently well from the feedback I get from my users.
Where this feature would be especially useful too is idioms and collocations ("words best used together"), not just full sentences. It's something that's not often addressed in formal language learning but a big part of native fluency. And yes, it's a lot of data. Though it could be made manageable by e.g. importing it from external knowledge graphs/mindmaps and the like.
In my experience, the brain collects background statistics on collocations through exposure to native media. It's an aspect of language learning I'm not convinced SRS is suited to or really appropriate for.
I wrote my own spaced repetition app (see my profile) and one thing I experimented with is an "ETA" function which goes through your deck and tells you how long before you learn everything "well enough", where "well enough" just means the intervals between all cards is at least some fixed threshold, like one month. I was surprised that even with a few hundred cards and a fixed number of cards reviewed per day, it would still take a few months.
I haven't added the ETA feature yet, but if I do, I think I would need to make sure to show the user how adding new cards affects that target date, and also how reviewing more cards a day or fewer cards a day affects it. I think there's a way to design a nice UI so users feel like they are in control of that end date so they can choose if it's worth it to add new cards or not.
I think a spaced repetition app should also make "falling behind" not feel catastrophic. I think memorizing a smaller set of facts consistently is better than trying to memorize a larger set and then giving up, and an app's UI can probably help to that end.