Not sure if here is the right place to ask, but anyway:
When I started using Duo, I took an initial test in Polish and I was assigned a 3% fluency. A couple of weeks later, after many lessons and tests passed, my fluency went up to 4%. The next day it went back to 3%. Then for the next 2-3 weeks during which I never skipped a day and passed many tests, it stayed at 3%. I think I'm about half the way through the course. I already had a good knowledge of Polish before I started the Duo course, so I'm advancing fast. Mostly I'm testing out of the topics. Could that be the reason my fluency percentage doesn't change?
Several forum members (including me) think that the fluency indication is very inaccurate. I simply ignore it.
I think you have a good feel for how well you are doing if you do your lessons and see how many questions you have to repeat. For an assessment of your language skills, you might take an online test offered by an official institution. For German, this would be Goethe-Institut. I don't know what the equivalent institution is for Polish ...
I am a Polish native with fluent English and I've just taken the full Polish test to see what kind of questions are there and whether the pronunciation is correct (well, I was mildly surprised ;-) ). After finishing this test (with two typos only), with almost all circles golden I got as much as... 1% fluency. So just ignore it and focus on learning and trust your gut feeling for your fluency. Also have some chat with natives. It's much more important that you can effectively communicate than the fluency you have according to Duolingo.
Thanks for your reassurance! I can easily read Polish news and fiction so I thought that 3% was a little too conservative. ;) But I was also surprised that no matter how much I learned on Duo, this number didn't change. I guess you are right and I should simply ignore it.
I think that you're right and it's mostly because of testing out. I am 19% fluent in Portuguese (as far as I remember), despite doing about 20 skills and not touching them almost at all for like 6 months. Generally, a very redundant option.
I took a French test from scratch and went straight to level 10 with a 59% fluency (I've been learning French for most of my life). OK, that's reasonable. But my Polish is about as good as my French, and I'm also at level 10... but with a 3% fluency. Does this make any sense? Not to me. I tested out of French just as I tested out of Polish. I really don't see any correlation between the fluency percentage number and the actual mastery of the language - not even with the level also assigned by Duo. Not that I am complaining but Duo suggests posting this fluency percentage at LinkedIn. I'd really want to do that if only this number had anything to do with the reality. This could be a nice feature. It's a pity it doesn't work.