Languages, yes. There are plenty of pre-made decks for learning the basics of pretty much all the major languages. Beyond that it's a mixed bag. There are usually decks for things like verbs and common nouns. Getting comprehension practice (e.g. grammar) is harder because that only comes with ingesting lots of material from different places (otherwise you tend to 'overfit' and rote learn the flashcards).
Making your own cards is more effective than using someone else's deck, simply because it's tailored to you. For anything other than a language, unless it's pop trivia, you should try to make your own cards. You typically have to work methodically through the thing you're trying to learn, which can help a lot. If you go with a pre-made deck then you're relying on what someone else thinks you ought to know.
> Getting comprehension practice (e.g. grammar) is harder because that only comes with ingesting lots of material from different places (otherwise you tend to 'overfit' and rote learn the flashcards).
That could be solved by not treating flashcards as units of knowledge you need to memorize, but as tests that you can only pass if you know a certain set of things. Then you would simply add new things to learn (e.g. vocabulary, grammar rules) and the system selects appropriate flashcards from a large set of examples to test your knowledge.
I've been working on something like that using example sentences from Tatoeba, but I didn't get very far yet, partially because defining the set of learnable grammar rules for a language I do not speak yet is a bit difficult.
> There are plenty of pre-made decks for learning the basics of pretty much all the major languages.
I tried a few of them and the quality varies. The Arabic one I tried was very funny, it would show you something, like أ, and then ask: does it mean "Alif" the letter o does it mean: "How much wood would a woodchuck chuck if a woodchuck would chuck wood? A woodchuck would chuck how much a woodchuck would chuck if a woodchuck would chuck wood".
For me writing things down by myself is a huge part of the learning process (I take notes by hand in class even though I'm fluent enough with LaTeX to take them on my laptop directly) so I've never tried decks of flashcards made by other people, but you can find plenty of them for languages, divided by level or topic.
Personally I used Langenscheidt's Basic German Vocabulary¹, which contains the most common 4000 German words, further divided into the top 2000 and the 2001st-4000th and by topic, with example sentences for all of them. I made a card for each of the top 2000 words and included the example sentences in the cards as well.
Yes, there are. Learning a language via anki is best by first knowing what all the common phrases and words used in 90% of the language's everyday use is.
This is usually a google search away.
Premade decks are really good for starting off, but ultimately making cards pays off more in the long run for associating memories to individual cards. This comes at a cost of a longer setup time and ongoing process, but with this you can guarantee all your cards are of high quality caliber.
I have my own CSS Stylesheets on my cards too its helpful by visually associating different colors for answers. I use a variety of different formatting techniques too for faster visual grokking/grepping of cards
Both; success rates are significantly lower if you use somebody else’s cards. Seeing the card you made reminds you of making the card, which helps you remember the information you were trying to capture at the time.
I study maths and I never thought about using flashcards for it, but it's a cool idea, I might try it out!