I think that in practice these norms will be hard to enforce just by culture. I would recommend a few things:
1) like the discourse.org forums, remind people of these norms a few times as they get used to the platform. Discourse shows this message to new users the first couple of times they go to comment. Something similar here might make sense.
2) make it easier to do the things you want to incentivize, and harder to do the other things. For instance…
If you are one of the first people to dislike a page, please leave a comment telling the author why you disliked it. It will help them improve.
So maybe make this mandatory. In order for the downvote to register, you need to type at least 5 words of why. There could be a dropdown or something to make this easier, so you could just pick "I found this hard to read; get someone to edit it before publishing" or "this is snarky in a way that seems likely to provoke more rage than productive discussion" or "I want to plaster (citation needed) on your entire page". Maybe only for top-level pages, and maybe only for the first downvote or two. But still.
Similarly, we might ask how to effectively incentivize each of the other items on this list.
The terms—"like", "vote", etc—will probably play a role here too. As much as you can try to define them, other connotations and associations will sneak in. The ones chosen seem okay, but I wonder if something else mightn't work better… perhaps "high quality"/"low quality" instead of "like"/"dislike" and "bet" instead of "vote", although I only spend a few moments coming up with those.
Comments
Alexei Andreev
Yeah, good points! We are still figuring out the norms for the discussion, and how it will ultimately be converted into pages.
I'm a bit torn on making things mandatory, since that's annoying, and I can see many instances where people downvote because the content is just obviously bad, and nothing needs to be said. Shouldn't be an issue for a while.
We've spent a lot of time thinking about alternatives to "Like", and we've considered "high quality". Quite possibly we'll move to that once we add "dislike" and other voting mechanisms.
Eric Bruylant
+1 for requiring feedback for downvoting. The original poster thought it was a good thing to post, and unless they are given a reason they won't know what they need to fix in future. Also downvoting is really bad for participation (that's why it costs karma on stackoverflow), so creating an imbalance between ease of downvoting and upvoting seems positive.