When do we really know a word

*update - I removed this post as I didn’t realize there was already one up on the same subject a few days ago…

I’m fairly new to LingQ, so don’t take my word as gospel, but I’ve noticed that every time I review words in flash cards (or the other study options), they move up one point on that scale. So “1” words go to “2”, “2” to “3”, and so on. The system seems to assume that after you’ve reviewed a word so many times, you know it. Overall it works for me, although I have more trouble with some words than with others. If I don’t think I’ve learned a word that well, I’ll just move it back down a point or two…