Revisit old lessons until finish with full hearts OR just plow on?
I was just wondering what you recommend as the best approach to learning with your lessons. Should I keep revisiting lessons until I finish them with full hearts, having made no mistakes? Or should I move on when I finish a lesson and just forget about the fact that I barely squeaked by on that last German lesson?
My advice would be to keep going and go back and practice. It'll be more motivational and you'll learn more words by moving forward. Then go back and practice the lessons or your weakest words.
I think you need to balance between them. Do a few new lessons, review a few old lessons which have degraded.
There was a large discussion on that: http://duolingo.com/#/comment/223366
It inspired me to go back and get my full hearts for every lesson. I found that I don't remember a lot of words because I always moved on after barely passing the lessons. I'm almost finished with the previous lessons and from then on, I'll be getting full hearts for every lesson before I continue.
However, as far as I understand, the new system which is coming soon has no hearts but only strength indicators.
I go back if I have 0-1 heart and move on with 2-3 hearts, but I also practice my "weakest" words every day before I do a new lesson.