"Weakest Words" doesn't include my actual weakest words?
Maybe the algorithm just needs some tuning, but I feel that the way "practice weakest words" selects my words is a bit erratic. It almost never pulls in the words I've learned recently and I need to actually go into the lesson (ie V. Pres. 1) to practice the newer terms I've learned that I'm actually weak with.
for me, it's the other way round. According to ruinchristmases example (mastered subject A, have learned subject B, and are am learning subjects C and D) it would give me really easy sentences from A and B, which consist mostly of stuff i know pretty well.
I find that the deeper into the lessons I get the better duolingo is at letting me practice the newer words. Especially if you follow the stared lesson plan instead of mastering one lesson at a time. My problem is that sometimes you don't see a word for over a month and I can forget it.