If someone gets a phrase correct, how many more times should they practice it?

Question

I am creating a language curriculum for Standard Chinese (none exist in my area). If someone gets a question/phrase/word incorrect, for example a phrase from a module on greetings, they should obviously see that same phrase or a different phrase with those same words, again until they don't forget it (using spaced repetition):

A student should meet a word every x, x+5, x+10 minutes to ensure retention

But my question is... what if they get the phrase correct on the first try? Can I assume they've got it and move on? Should I assume it was a fluke and verify? If so, how many more times and does it still follow the same repetition curve/timing?

For example, some implementations of SuperMemo algorithm (such as Anki) take into account getting things incorrect and correct. How is this done?

Answer 1

According to research that I cited in this answer, "a typical learner should meet a word about 8 to 10 times to obtain full word knowledge" (F. Rasouli and K. Jafari: "A Deeper Understanding of L2 Vocabulary Learning and Teaching: A Review Study", International Journal of Language and Linguistics, 4.1 (Jan. 2016), emphasis added).

So it seems that you will need to present correct phrases several times before you can assume that they are stored in long-term memory. However, it seems a bit strange to present an entire module again if such a module contains several phrases (all of which presumably need to be correct), one of which has not been learnt correctly. From the point of view of space repetition systems, the modules may not be "atomic" enough.

Since phrases that were memorised correctly still need to be tested again, the next question is then what algorithm to use for determining the time between the previous "test" and the next. There are a number of algorithms for this, for example:

• Anki uses an algorithm bases on SuperMemo's SM-2 (see the Anki FAQ).
• The page SuperMemo Algorithm discusses various algorithms that SuperMemo has used so far.
• The page Spacing Algorithms and Implementations discusses algorithms used in Mnemosyne, Anki and SuperMemo.

I cannot give you a recommendation for a specific algorithm, since this requires research that compares their effectiveness, which I do not have at hand.

Answer 2

You just need to come up with algorithm, why not? Take a look at some research about the problem you are facing, and implement the results of research in your code. Why not?

Example. I read somewhere, sorry I couldn't find the source, that if one wants to memorize the word for a long period of time, phrase in foreign language, s/he should face the word, phrase more than 80 times.

On the other hand, insisting learners to say 80 times the phrase they have already got, can cause other problems as losing your users because of boredom of your software.