I had a random question about something that has been bugging me. In the progress stats, I'm always about 20 characters and 10 words short of "knowing" all the words and characters I've added. I think I read elsewhere in the forums that "knowing" is based on being able to retain for about 12 hours, before I always figured I had about that many floating around under that time window.

However, I haven't added any new characters or words in about three weeks. I've just been reviewing old material, almost all of which is at a two or three week or longer interval. It seems like if there were still 20 characters under a 12 hour window, I would be seeing them all the time and know which ones they were, but it doesn't feel like this is the case. Am I missing something?

Hmm, let's see.

So on your progress page it says you have unknown:

7 words
14 characters
10 tones

Well looking at tones, I was able to find 11 tones that aren't yet learned. These are

518 令
974 职
1782 防
4260 派
7216 守
8073 辞
15300 虽
23314 君
25382 深
33402 抹
33497 相

The numbers are the number seconds between reviews. All but 职 are not being studied by themselves, so they only show up and get studied as part of words. So it appears the number for that is 1 off.

As for runes... well I can only find two that haven't been learned:

267 挠
13127 哲

These are also only studied as part of other words, so they don't show up by themselves.

But this means the number of characters being learned is off by 12, and the number of words being learned, off by 7, and also tones off by -1. My guess is these are errors cropping up in progress tracking over time. It probably has to do with the fact that updating overall progress and updating the progress of the individual word are updated separately, and so not necessarily both happening, if one throws an error and doesn't get a chance to retry, for example.

Given all this, the progress page then has to be looked at as having a small margin of error, which is fine most ways you look at it. But when you take the difference of those two numbers, that makes the margin of error much larger.

Also, the progress tracking includes items that are being studied indirectly, and items that have been deleted. So if you study an item, but don't learn it, then delete it, it will still be considered added but not learned. And there can be hidden items that are added secondarily for tracking as part of a word, like most of those listed above.

We could make as robust a system for progress tracking as we could come up with, but that would take a lot of time, and it would probably only make the margin of error smaller, not non-existent.

Alternatively, we could make a page where it recalculates your current stats from the ground up, collecting all items and tallying them up for you. You couldn't use it to calculate your stats in the past, and it would take too long to calculate to put it first thing in the progress page. But it would give you entirely accurate and more specific data if and when you want it. Not something that's going to be high on our priority list for a while, but how does that sound for a possible solution?

Wow - impressive response. I think I may have overstated my level of concern... I was more just curious why I never seemed to be able to catch up to knowing all the characters. I don't think adjusting this should be much of a priority at all. It might be nice to have some indicator that it isn't precise? Although I'm not sure how you would do that without making it extra confusing though.

Thanks for the response, I'll stop trying to get those two numbers to line up!

Well I like to know when thing aren't lining up correctly, and why! So it's time well spent doing some research and sharing it.

Well, could add a little note to the progress page to mention that there's a margin of error. We'll be reorganizing the progress page somewhat not too long from now so that people can view reading and definition progress, and maybe that can be part of the new design.