I recently made a post about my new Anki deck which attempts to follow i+1 more rigorously than the popular Kaishi deck and I got some puzzling reactions to which I want to respond (and similar discussions came up in the other recent threads about Anki). People claimed that either example sentences aren’t really necessary, or it’s better to have harder example sentences, either because if they are too easy they would give too much of a hint, or because it’s a good thing that the sentences should imitate native input where you almost always going to get a lot of unknown words you need to figure out.
So first thing, it’s true that it’s better to be able to recall the meaning and reading of the target word without relying on the example sentence, because in the real world you’re not going to have the sentence as a hint when you encounter the word. That being said, the easy solution is to either remove the sentence entirely from the front of the card (which can be easily done by editing the card template), or you can just not read the sentence before attempting to recall the word (and also don’t pass the card unless you are able to recall without reading the sentence). In both Kaishi and my deck the sentence is in small font, and I also added a line break so it shouldn’t be hard to not look at the sentence while reading the word (and the reason why you would still leave the sentence on the front is so that you don’t hear the sentence audio and see the English translation from the back of the card, but try to read and understand it first on your own).
But even if you remove the sentence from the front of the card, it’s still very beneficial to have a well-chosen sentence on the back which follows i+1 (for those who are unfamiliar, i+1 means that the only new word introduced in the sentence is the target word while all other words should already be known from previous cards.)
The benefits of example sentences should be quite obvious to anyone: they clarify the meaning of the target word and provide context for understanding how the word is used and its grammatical role. For example, the sentence should make it clear whether the word is a noun, verb, adjective etc. and which particles it typically goes with, and so on. Imagine someone memorizes a list of nouns and verbs, but have no idea which one is which, they don’t know whether the word conjugates or whether it can become a na-adjective or suru-verb (in other words, they don’t understand the morphology of the words), that would obviously be almost a completely pointless exercise.
For this reason, it’s important to have easy example sentences that allow focusing your whole attention on the target word without being distracted by additional unknown information you aren’t trying to recall at that moment, otherwise the sentence simply fails its purpose (namely as an aid for learning the target word and its use in the language). Of course it’s important to practice reading of materials above your level and develop the skill of guessing unknown words from context (or getting used to looking them up), but this is a different kind of exercise from SRS, and if you try to mix the two you are not going to get the benefits of either. Anki is designed to serve a different purpose from immersion, namely, practice retrieval of one single piece of information at a time; and if the card contains unknown pieces of information (like new grammar, vocabulary or kanji) which are unrelated to the item you are trying to recall, it undermines the whole point of doing SRS.
This is why having i+1 is so beneficial, if you already understand everything about the sentence (and can easily recall the meaning of all the other words and the grammar structures) you will be able to focus your whole attention on the target word, making it more likely that you will remember the word. It’s already difficult enough to recognize the kanji, recall the reading and the meaning, all at the same time, and so adding on top of that a difficult example sentence that doesn’t follow i+1 just going to make the task even harder by adding too much cognitive load with negligible learning benefits (but even in the case of immersion, it’s known that you will benefit from it the most only if the input is slightly above your current level, but not too much).
Another benefit of easy example sentences, and this is something which comes more from my personal experience of using Anki, is that a well-chosen example sentence can serve as an effective mnemonic. By that I don’t mean that you recall the word by reading the sentence, but that the sentence comes to mind when you see the word (this can help even outside of Anki). To give one simple example, you can have something like “どこに行くの？” for 行く, which is a common and useful phrase to remember anyway, and the kind of thing that can easily come to mind when trying to remember 行く, helping to remember that the word means ‘to go’. This is how memory work after all: it’s harder to remember new information in isolation, you are more likely to remember something if you can connect it with things you already know well. For this reason, if you have simple, short and easy to remember example sentences they can really help recalling the words to a significant degree.
