Let's say there's a character 聚 that I have forgotten. I haven't reviewed it in months, and it's due in 1 week.

A new character 骤 appears today. 聚 is a component of 骤, and I'm reminded of how to write it. When 聚 appears in a weeks time, I get it right. It's then scheduled for many months in the future, even though it was forgotten just recently. (This could also happen when reading. Encountering a character in a book, just before it's due, would assist in recalling how to write it.)

Sometimes I mark these reviews as so-so or wrong, but sometimes they pass me by.

Thoughts?

I know what you mean. But then you've essentially reviewed it twice in the form of 聚 and 骤... so hopefully after those two you know it better?

In order to improve my retention I try to review without adding words for awhile.

I would like a feature where Skritter could find all characters where I have gotten them correct less than 80% of the time, and add them all to scratch pad. There are some characters that I mess up a lot, but I got them correct the last two times in a row so Skritter doesn't make them due for months. Of course 4 months later I mess them up again and I really don't remember the character for any of the time in between because I haven't mastered it.

Perhaps I'd know it better. But like you say, I'm likely to forget it again before it's rescheduled.

If you forget the character before it's rescheduled, then when you do end up reviewing it, that will strengthen your memory of that character more than if you reviewed it sooner. The longer the delay, the better for your long-term retention. Although I agree that Skritter and other spaced-repetition tools could do a better job of detecting and mitigating interference and priming effects.

As for reading, if you are exposed to a given character often enough outside of Skritter that you never get it wrong, then you probably don't need Skritter for that character.

jww1066, I think you have a point here. It seems the original poster would like to maximize the effect of the spaced repetition method in an isolated environment, whereas my primary goal here is to use Skritter as one of many ways to study Chinese. So I wouldn't blame the occasional business owner in the street for presenting an almost forgotten character in his company name to me at an inconvenient time in my Skritter schedule ;-) If Skritter itself does the same unintentionally by showing a new character containing another one which I have studied before, I'd see it just as that - an unrelated, yet welcome opportunity to ponder this character. Go with the flow, relax, just don't sweat!