How does Skritter distinguish wrong words vs characters?

This is a source of confusion for me. Usually I know the character, I've just forgotten which character is in a certain word.

I tend to just mark the character I forgot as so-so. I'm not sure if this is the best thing to do? I guess I don't want to review the character again, just the word.

How should it work?

It's not done now, but before too long it will work something like this:

If you get the character wrong, Skritter will try to determine based on how due the character is whether you would have forgotten it or just that it was that character. Depending on that, it'll either mark the character wrong or not. (The word will be marked wrong either way.)

For tones, if you put a tone that is correct for that character but not in the context of that word, it would mark the character right and the word wrong.

Right now it doesn't do these things and just builds the word's score out of the individual characters' scores. Still working on it.