I have noticed many, many times that on the multiple choice questions (learning French), the alternatives given include nonsense, allowing a student to choose the correct option by eliminating the nonsense. In my experience as a teacher, multiple choice options should always be plausible so that they could potentially distract the student and therefore test real knowledge.
I have seen different kinds of nonsense. Some sentences are just too bizarre to be plausible, even on Duolingo where "He lives in an apple" can happen. I doubt that "She is wearing a sandwich" is a real option.
Other sentences literally make no sense, like "He raises the heat down". Raises and down can not be together.
Other sentences are just grammatically incorrect, like "She is eating an baguette".
I have reported literally dozens of these sentences to Duolingo, but isn't anyone thinking before constructing such nonsense phrases?
The trick here I think would be to only show grammatically correct sentences in the source language (e.g. don't allow "She is eating an baguette"), but do show grammatically incorrect sentences in the target language (e.g. allow "Elle manges une baguette" if testing for conjugations of manger).
The difference here is to knowingly test for some specific knowledge instead of simply providing three sentences, one or more of which may be right. A subtle but a very important difference.
This process might even be open to automation too, by using the most common incorrect translations that users provide.
I'm sure the incorrect translations are just generated automatically. They replace one word with another and voilà! That is why they are so ridiculous most of the times.
The idea to use users' mistakes seems great! It has to be tested, though, because there should be some engine that allows to select seemingly fine, but really wrong sentences. It won't be good if Duolingo gives you an "incorrect" option which is only incorrect because it has not been added yet.
I really like your idea of automation - multiple choice questions are supposed to test student's management of relevant details, so the aspects that they often get wrong would be great "distractors" or wrong answers. I wouldn't be sure it would work, but it could be beta tested.
Naturally there is nothing wrong with offering some grammatically incorrect options in the target language, but in the base (and usually native) language it's pointless - for native speakers, it's just nonsense, and for non-natives it tests their knowledge of the wrong lang.
This is also the case in Spanish and Italian lessons. My suggestion to them would be to look at common errors students make--even sentences that are commonly reported as "should be accepted" but that are actually mistaken! I think a lot of problems we are seeing in the "pedagogy" side of the trees right now is unfortunately based on the fact that Duolingo have overreached themselves a bit and are relying too much on automation to sort sentences.
I completely agree. At certain times, the multiple choice gets tedious and vexatious. When that happens I simply eliminate the nonsense answers just to get to the next question and continue the lesson. Although I did come across some questions that made me double check my answer because there was a small grammatical difference between the choices.