I need help understanding Jukuu's rating system.

[LuDaibola]

I've been benefitting from Chinese-forum posts for a bit now and want to thank everyone for all of their useful advice and for the detailed responses to so many questions.  Thanks so much for taking the time to help those of us who aren't as far along on our journey (in fact, I'm just above newbie level).  Here's my first question:

 

I'm a self-learner and, currently, don't know anyone I can pass sentences by so I was happy when I recently discovered Jukuu (I noticed that GrammarWiki utilizes it).  I began to use it to find new sentences for the vocab I'm learning but, after noting that they have a rating system, I've begun to worry about whether I can trust their sentences.  Each sentence is rated--presumably by registered users--as either positive or negative.  I'm wondering if any of you have a sense of what this rating means.  Is it on the order of YouTube videos where, no matter how good the video is, a certain number of people downvote it.  Are the voters saying that, yes, this is a good way of expressing something and I can trust that if 12 out of 14 voters saw it that way it's probably worth learning.   Or should I only use sentences that no one has downvoted.  This may be explained on their site but since my Mandarin is very limited I'm not able to find it so am hoping someone here has some insight.  謝謝一堆 (and that came from Google translate which I'm sure I can't fully trust!)