As I see it, this covers three topics.
One way I see of making the collaborative nature of Slant more obvious is simply by explaining it through a banner/warning somewhere on the question page for people that haven’t logged in. And, additionally, setting up a one-time signup email (or a notification directing to an about page) explaining how the site works more thoroughly.
Could also surface more of the discussion, community interaction process to show that there are people working on this.
Could add question level leaderboards.
Or show more of how the site is built. If a person knows it can be edited, improved or flagged by anyone, maybe it becomes clearer that it’s a community effort.
Imo, to truly figure out that the community has trustworthy members, the content has to be tested by the user. There can be indicators of status, but I don’t think true trust can be gained without some sort of a successful leap of faith. For example, downloading an app and it being just as described.
Status can of course help, and to show that, there can be flairs, badges, different colored avatars or follower counts mentioned.
But again, I don’t think something like reddit’s comment karma is a definitive measure of trustworthiness. While it can still be a helpful indicator.
And I have to mentioned that there are pressure and attribution issues that arise from associating content with people that will be more pronounced with these solutions.
While some of the ways of encouraging contributions that come to mind are more gamification, ability to say “thanks” and granting the ability to create a following, the three that I think are more important are explaining the value of contributing, removing the high cost of participation and creating a sense of community.
I think we should be explaining the value of contributing, because I don’t think it’s as obvious in our case than, say, Wikipedia’s. It could work in tandem with the banner that explains how the site works. I believe we already have mockup for that with a great inspiring chain of events.
I think we should be removing the high cost of contributing good content that’s imposed by having to register. I think we’re missing out on so much good flyby content. If not remove the restriction, how about making it simpler by asking for an email address to make changes? “Enter an email to submit changes?”
The last part about community building is I think self explanatory and I’ve mentioned before how I think we can get there with moving the comments system to a more visible position.