Czech is at 100%
I was just checking the courses and saw that Czech is at 100%! If it is that high, why won't it enter Beta until July? I'm really excited to explore this language. Just spreading the word!
The estimate is automatic. If the course's creators do not work from a bunker (the Czech team, apparently, does not) the best way to get a realistic estimate is to ask them.
What Duolingo does is dividing the number of words that have sentences by the total number of words in the tree.
Now, unless you start making your tree by filling up the course with 80 dummy lessons 25 words each, there is no way such estimate is going to work during the final months of the development. In fact, if you were to have, say, 1980/2000 words completed (which is 99%), the percentage would DROP if you added another hundred and made the sentences for 50 of them (it would become 2030/2100, or about 96.7%).
- another fun observation: 1900 words out of 2000 and 2850 words out of 3000 are both 95%. However, it may take half a year to go from 1900 to 2850.
- when the team starts making the course, they do have a greyed out template (we had an English one). It sort of works at the beginning but, obviously, as soon as you reach the latter rows, throw out the dummy skills and start adding your own stuff at the end, the percentage the users see starts to jump up and down.
The update posted less than a day ago says they are about 95% complete. It seems that they are close but not finished yet.
Shady_arc's explanation is spot on. We may be at least 6 skills short of the finish line. Those extra skills are empty, nothing but placeholders at this time. At some 30-ish words per skill, this may mean another 200 words or so, a revised target of 2,100 words, and a merely 90 percent completion, no matter the misguided bells and whistles displayed by Duo.