At Math Academy (https://mathacademy.com), we implement spaced repetition in combination with a knowledge graph consisting of several thousand math topics and tens of thousands of connections (and growing). We're working on a post that explains how this all works technically.

We have a Linear Algebra course (https://mathacademy.com/courses/linear-algebra) that some of you might find interesting given how often that topic shows up on HN, and we just finished our Math for Machine Learning course (https://mathacademy.com/courses/mathematics-for-machine-lear...) for anyone who might be interested in giving that a look.

I'm the founder if anyone has any questions.

Sorry about the shameless plug.;)

Really nice to hear knowledge graphs being used for... learning knowledge.

Is there a way to try it out (at least for a week) without paying the $49?

There's a 30-day free trial, so if you cancel during that period you get a complete refund.

I'm the founder of Execute Program (https://www.executeprogram.com), where we've done a similar thing (knowledge graph + SRS) for programming languages/tools since 2019. Interesting to see that you have a graphviz render of a subgraph right on the landing page! We've toyed with the idea of exposing the graph visually, but haven't done it yet.

The UI/UX of executeprogram is genuinely amazing and the way lessons are broken down is extremely well-thought out!

Definitely recommended for anyone wanting to learn JS/TS, regex, and SQL (especially in conjunction with Jennifer Widom's Intro to Database lectures).

(Given your background with Ruby, have you thought about doing a Ruby course? I find it relatively easier finding resources for JS, Python, and even Rust. I imagine you could make an amazing Ruby introduction, though perhaps it would require more work than JS/TS than I would expect.)

Hi,

Given that SRS is a long-term endeavour, going on several years, I'd balk at paying $49/month for your app. Maybe $60/year, but your current pricing is really hard to swallow.

This is very, very neat. I've seen a lot of cool looking learn math sites that stop after (best case) freshman college math. I have a BS in math but there were some courses I never felt I got or it's been so long (>10 years) that I've forgotten more than I'd like and it'd be really nice to brush up on the interesting stuff.

I'm very interested in your methods of proofs and abstract algebra courses and I'm excited for them to be released!

That would be a fun post to read - is there a link to your blog?

I’d like to add Mochi to the list https://mochi.cards/

It’s just a standard flashcard tool like Anki, but with a much better user interface and a simpler (IMO superior) SRS algorithm.

totally love it as an alternative to Anki, didn't mention it since it has already been praised by the original post

And a subscription required for key functions like multi-device sync.

I would not call Duolingo a language learning application. It behaves more like language mimicry application. You learn a very particular subset of the language that I'd call "Duolingo <insert lang>". This is my conclusion after using it for two non-English languages.

You seriously need a basic beginner book if starting from fresh, and use Duolingo just as a repetition tool when you can during the day

Consensus among Serious language learners (i.e aiming for a B2+ level) is that duolingo is marginally useful for learning some vocabulary. A thorough course or textbook are essential

I agree.

I used it for most of a year, and from what I can tell they go out of their gamified way to not teach any grammar or even vocabulary. Not all the time but ~20% popping up sounds and spellings, but providing no way at all to know/check what the meaning is... Why? Why not have a dictionary of the words you've "learned" and will be tested on?

Going to a fixed sequence of learning "the path" so that you're forced to cover topics and words in a specific order, and then introducing grammar that has never been taught... Why? Either cover them in order, or don't.

Eventually, you figure out the right answer by trial and error and "learn" it, but only after having developed a bad habits and wrong answers... Why? Of course there are Anki's and such out there that cover all the words so I guess they want you to just do that.

I'd say the answer is because they don't measure success in terms of who becomes competent in the language, but in how many users they have. typical neoliberal "number go up" mentality, rejecting ideological definitions of "genuine" value

https://youtu.be/m8Mc-38C88g?t=176

If you're learning Duolingo subset of a language, it's still a language learning application.

It's more like a side quest rather than main story line. And that's okay.

Duolingo gets a lot of hate.

You can pick a lot worse to learn to be able to stumble through a language for vacation.

Learning the first few words in a language to start becoming competent in it is not a bad thing. Managing one's expectations is really important.

Not all learners will learn best with a textbook or course first. Variety helps.

Humans have learned language by speaking before as much as, if not more than reading/writing.

Now, are there better apps coming out for this kind of thing? Absolutely. The potential for LLM to be able to generate and listen to pronunciation will be amazing.

Prioritizing speaking before learning to read or write a language really seems to irk some folks.

I realized that, after a year of learning German on Duolingo, the app had become something that I hated. The initial gamified fun-ness became a stressor. Seeing the notification every night that my streak was about to end stressed me out. I had long since stopped enjoying the learning process because it had felt like I wasn't learning anything at all. Ending my streak felt amazing.

I'm learning Japanese now through books, Anki, and a few webapps. The gamification is gone and streaks don't really matter. I'm sticking with it because I'm enjoying learning, not because the owl is threatening me.

I found Duolingo very good while I was actually in the country and speaking the language I was trying to learn.

It didn't teach me to speak alone but expanded my vocabulary enough to stumble through conversations. Which was enough to being improving through speaking with locals.

What alternative would you recommend?

As an aside, LogSeq is quite good at creating cards for spaced repetition with just a hashtage and a cloze as you write your notes. I would expect other tools like it (Obsidian, etc, can do this as well)

Agreed. Logseq changed the game for me. Because SRS is closely coupled with note-taking and is as simple as adding "#card", it eliminates any friction and excuses I had for not using SRS. I look forward to adding new cards as much as I do reviewing old ones.

Another use I'm discovering is using logseq in this way for both cards, and annotating explanations of things that can be put back into other learning content.

wanikani.com is a good example for the very specific market of "English speakers memorizing Japanese kanji." Great UI, great community, great sense of humor, well thought out mnemonics...

...and of course I still fell off the wagon after a few months, came back to a backlog in the thousands, and have had tremendous trouble getting back on the wagon.

WaniKani I found filled my head with meanings that didn't correlate to anything, and knowledge that wasn't actually useful.

I am by no means a Japanese expert learner, but I am having much better luck just memorizing real vocab without that intermediate step.

As someone pointed out about the much famed "Remebering the Kanji", you could remeber all the kanji perfectly and still not be able to read Japanese, because Japanese kanji is not equivelant to vocabulary. Actual words, pronunciation and meaning all change when you combine kanji into words.

It's good tangential knowledge to shore up your learning, but it's not something you should spend your entire focus on before you start learning the actual language of Japanese.

Agreed. I pulled the top 1000 Japanese words and then entered those along with the specific kanji readings. Learning wonky kanji readings is for those masochists who want to pass JLPT Level N1.

You want to memorize in usage order as you are, nominally, an adult. You understand complex concepts and have developed motor skills. There is little point in learning in the order that a child would.

If I remember correctly (ha), WaniKani is actually ordered by the simplicity of the kanji, as they also point out that children can only start with simple concepts but non-native adults have the concepts covered but will struggle with complex kanji.

You do. Most off the early levels are kanji that a first grader would know, and it very loosely stays organized by grade level, with a lot of allowances.

The true masochists go for Kanken level 1 (which has almost 90% fail rate even for native test takers, and those are already the self selected sample of people mad enough to try the test).

Remembering the Kanji is for learning how to write kanji, which does help with reading as well, but that's not its primary purpose. If you actually do want to be able to write by hand (which I think most people (understandably) don't want to invest the time for), it's well worth the time investment.

> it's not something you should spend your entire focus on before you start learning the actual language of Japanese This is also true. You can do both. In fact I think you /should/ do both, learning new vocabulary using the kanji you've learned so far to help motivate you to learn more. It's quite addicting when you can see your progress day-to-day.

I struggle to learn chess even with repetition. Very slight difference on the board required drastically different plays. It is almost as if there is no pattern

For language, I can vouch for both Clozemaster and Lingvist as very polished tools that put the spaced repetition front-and-centre unlike Duolingo.

I've tried Clozemaster several times and always uninstalled it within a few days despite really wanting to like it. I could happily ignore the bad UI if the functionality were good, but I've found that the pacing lacks structure and a sensible learning curve. You'll straight away be given bizarre sentences with complex grammer which is unsuitable for your level (in my case, beginner to beginner / intermediate depending on what language I've tried). For all Duolingo's faults, the learning curve is at least well suited to beginners - the first few lessons are always very basic and it builds from there. I felt like Clozemaster was only suitable for someone who has already learned the language and simply wants to build vocabulary.

My experience with Lingvist was the opposite. The UI feels polished and the sentences feel natural and comfortable to learn even for a beginner. It's a shame that it's so expensive - I'd quite happily pay $100 or so for a lifetime membership but sadly they don't offer that.

Want to add Hello Chinese: http://www.hellochinese.cc/

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I can understand pay for supermemo, but it is not in list.

Regarding chess, another one is https://chess.braimax.com

I'm a big fan of the Recall plugin for VS Code.

https://marketplace.visualstudio.com/items?itemName=frenya.v...

You get all the code highlighting and markdown support built-in to the IDE. I used this plugin when studying data structures and algorithms for cracking faang interviews.

If you're interested in a more visual approach you can try https://traverse.link/ - it's an app I created which has spaced repetition, but really its goal is to cover the whole learning process, so it also has mind mapping and note-taking so you get a big picture view of what you're learning, why reinforcing bottom-up with spaced repetition