I have a question about how upvoting/downvoting sentences work.
I have "Sentence questions" activated and sometimes I get sentences that, for me personally, are not very useful. For example, when quizzed on 高血圧, I got: 高血圧です。For me, these kind of sentences don't help in understanding a word in context, but they are perfectly correct and valid sentences.
Another example: あれは古いお城です。when quizzed on 城.
I would like to upvote sentences that are useful to me to get them more often, and downvote sentences that are not useful to me personally, but I don't want to do that if downvotes mean "this sentence is wrong and/or not useful at all for anyone", because that is not the case.
So, are upvotes/downvotes personal and only affect one's own sentence choices? Or do they also affect other users?
Votes are global, although they are not visible. They are sometimes used (if they are ones written/controlled by renshuu) to prune sentences that are really disliked. Otherwise, marking it down will prevent the sentence from appearing for you.