Not too long ago (perhaps a couple months?), Duolingo added a "Fluency Badge", which you get in percentage increments ("You are now 43% Fluent!" I am not joking.) as you work through the tree. You can go backwards, just like your little golden circles can lose their golden status until you practice them again. I only discovered the "Fluency Badge" very recently, when I was bored and decided to work on the Spanish tree. At first, I laughed hysterically ("You are now 11% Fluent!" What does that mean, anyway?). Then I eye rolled. And today, I went digging around to find out why I never saw that on the Dutch tree. New feature, not rolled out everywhere yet. And then I found this comments thread.
a_david describes the feature and then the fun begins. One thing I've noticed about Duolingo is, that like nearly everything ever in the history of ever, way more people start than continue. And of those who continue, only a comparatively small number participate in the forums/comments threads. And it really seems like the more trees a person has worked on and/or worked up to a high level on, the more critical they are of the feature, of the concept that doing anything with Duolingo can make you fluent, or . . .
kamil.kryn says: "2 years ago I start Italian on Duolingo. I'm a meticulous type, I make my way through the skill tree inhumanely slowly (self imposed limit of one subunit a day). And then, about 2 months ago, I go to Italy. Surprised as I was - I spoke Italian. I. spoke. Italian. Given, it was a choppy version of Italian, full of stuttering, "eeeem"s and "aaaam"s, and as rudimentary as they get ("one pizza please"), but there I was. Understanding and speaking Italian. Full Stop.
Now the fluency shield pops up and tells me I'm 60% fluent. You know what? I felt like 60% :)"
This seems pretty reasonable to me. Is it the CEFR definition of fluency? (And, yes, critics of the fluency badge bring up CEFR: "While it could be useful to know the level of fluency we have achieved if it was based on a known or accepted measure such as CEFR but to just give a percentage of a very vague measure seems a bit pointless for an academically respected site.") Not at all. But it is apparently capturing some notion of what it might mean to be fluent, according to a general population of people who do _not_ aspire to be polyglots. Fluency, as understood by people who don't speak a second language well, is the ability to get through a transaction at a shop, or exchange greetings, or order at a restaurant after making sense of the menu. And that appears to be approximately Duolingo's intention with the fluency badge.
It's a little tricky, when you launch a new service or product, trying to use early adopters to get the word out about your new service or product. You can't JUST sell to the early adopters, because early adopters are finicky and fickle. They demand the moon, complain about having to pay for it, and then are dissatisfied once they have the moon: it's so big, where are they going to put it, also it isn't actually made of green cheese as they had expected. Very quickly, they are bored with the moon, and want Mars. But of course, once they get Mars, they'll complain about that, too.
Another dilemma for Duolingo is trying to figure out whether they should cynically market the service to people who show up, do a level or two, and never return, or if they should try to help people keep coming back and doing levels so they actually attain a level of proficiency that will stick and might actually be useful to them, whether they are traveling or dating someone or working in an ER.
The fluency badge seems designed to encourage people who are NOT finicky, fickle, early adopters -- they are not polyglots who are going to work through every tree in the place, complaining relentlessly about how someone this doesn't Count as language learning. The fluency badge seems intended to get the person who shows up to keep coming back and actually learning something -- and to help that person _feel_ like they are learning something, which can be really difficult with language.
While I, too, laughed at the fluency badge, it's really grown on me. I think it's a great feature, and I hope they refine it and roll it out more widely. Gamification of language learning strikes me as a really positive development, and I'd love to see more people participate.