Using multiple SRS can harm your ability to store the facts in long-term memory. You'll still manage it eventually, but it goes against the core principle of SR - showing your brain that cards keep showing up, even after long breaks.

So two SRS programs working in parallel will slow you down, and will take more time to review on. Just take one and spend that time to just do more cards or use other methods instead.

New vocab is first learned through core6k, as it grants you the ability to READ kanji in context (I know about 40% of the core6k words I've come across, but can't read them). After you can read real text, you just move on to..reading real text, which is where the rest of your dictionary will be formed from.

If that was the case everytime you opened a book would screw up the spacong.

I'm being entirely speculative, so if you only care about scientific evidence, you can safely ignore this post.

You're both correct. Using SRS is meant to help you remember with the least amount of repetition. Heavy usage, like reading, is what we all strive for, but when learning kanji from RTK1, you can't really read. Back when I was taking new kanji in RTK, when I encountered IRL (or, more commonly, thought of the shape of) a kanji I was supposed to know the meaning of but didn't, I'd often struggle for half an hour during class to remember, and when I finally did, it'd often turn out to be one of those kanji that have just entered mature intervals. When a week later that kanji showed up on SRS, I'd get it right, but would be reluctant to send it to the 3-month interval, since I had only gotten it right because of having seen it a week prior, and would either mark it wrong or hard - I knew I'd have no chance of getting it right if I sent it on a 3-month interval.
If I were to remember the kanji easily, instead of struggling, I'd have involuntarily decreased the interval Anki meant me to take (say, 28 days) to a smaller one (say, 21 days), making the next interval potentially harder and increasing fail rate for it(and next intervals are always twice or thrice costier when failed, when it comes to time).

Doing two SRS programs at a time will reproduce this effect, except it'll be happening always, not once in a while. And do the math: if Anki intervals are 1-4-15-28-90 (just making up numbers), on a normal schedule, you'd get to 90-day retention within 138 days, assuming you always answer "good". If you do double SRS, you'd be getting two reviews for the 90-day period, so you'll only have a 45 - day retention, and the intervals will not be steadily larger, due to interference. Thus, to get 90-day retention, you'd need to get to a 3-month interval on one program, which may or may not take longer, depending on how often you make mistakes with single SRS. In any case, it's better to just take the new Anki and adjust the algorithm accordingly, it'll avoid the interference at least.

PS: Great post vix.

Last edited by Fadeway (2012 April 04, 1:51 pm)

Thanks for the links Vix.