One way it could grade you automatically is by the speed of flipping the card (or entering the correct answer). If it took less than a second to confirm then evidently it was easy.
The AI cannot read my mind, there is no approximation that will work reasonably accurately here for "how confident was I in my answer", unless I input that myself.
If the window loses focus it would be able to pause automatically. If you are distracted another way, no big deal you will see that word again soon and unlikely to keep getting distracted on the same word. The benefits would outweigh the odd misfire.
Not to say that how quickly you can access it doesn't play a role in real life.
Either I don't understand the algorithm or it doesn't understand me.
Depending on what you're learning, you might vary those. For language learning, that works well imo.
Also, make sure to switch to FSRS. The old algorithm defaulted to "again" resetting a card to 0, while "again" in FSRS does show it again, but doesn't reset it back to being effectively new.
If you want to understand the algorithm, read this: https://github.com/open-spaced-repetition/fsrs4anki/wiki/ABC...
I like the design suggestions proposed at [1] and [2] for this particular problem. [2] in particular gives tooltips which are supposed to guide you toward exactly what the buttons mean:
- Again: "My answer was completely incorrect"
- Hard: "My answer was correct, but I hesitated a lot"
- Good: "My answer was correct, and I hesitated a little"
- Easy: "My answer was correct, and I didn't hesitate"
That said, you can also just reduce it to a two-button system: only ever use Again and Good. There is some evidence this works better, especially with FSRS which is doing enough machine-learning behind the scenes anyway that it doesn't need the extra signal from Hard vs. Good vs. Easy.
[1]: https://forums.ankiweb.net/t/how-to-prevent-users-from-misus... [2]: https://forums.ankiweb.net/t/how-to-prevent-users-from-misus...