detailed data about listening comprehension, reading, writing, speaking...
I was wondering if you could create a way for teachers to track how their students are doing on each area of communication (listening, reading, speaking, writing). Duolingo does a great job of incorporating all four of these types of communication and it would be wonderful as the teacher to see in which particular areas students are struggling.
I also think it would be wonderful if the teacher could have access to a specialized vocabulary list for each particular student.
Since I teach Spanish, I think it would be helpful if duolingo counted answers wrong that didn't have accents or the tilde. I can think of several words that mean different things depending on whether or not it has an accent (si, se, este, el, etc)