We've been using the term "contributor" to refer to Thinklab participants because it seems to make the most sense for projects that have been funded and are in the research phase.
However, given that we're changing the focus of the site from "leading an open research project" to "helping grant writers improve their research proposals", it seems that the better term for ThinkLab participants is now "reviewers". When looking at the homepage you can now see we have "benefits for grant writers" and "benefits for reviewers". I think this language will make the most sense for new users.
At this moment, the site is using both terms depending on whether the project is in the proposal stage or the research stage. However, I feel this is simply too confusing. I feel we need to pick one term. I'm leaning towards "reviewers", because it makes the most sense for the first part of the project. And that's where I think we're going to attract new users of the site. And at this point in time, that needs to be the primary goal.
I do not have a strong opinion here. Contributor is a broader term that fits well for the research stage, but less well for the proposal stage.
Users will be more familiar with the term reviewer. Do you want users to behave as reviewers (in the context of traditional peer review) or do you want to differentiate Thinklab participation from traditional review?
It's a bit hard to say how we want users to behave. Ultimately, the guiding principle is that we want users to behave in a way that results in the most efficient creation of value for society.
I think there are 4 general categories of contribution that could be given:
Evaluating proposals and other content
Giving feedback on proposals and other things
Actually doing small amounts of work (perhaps writing some code or doing some statistical analysis)
I think the first points fall more into the category of review while the second fall more into the category of contribution. I do think review could be considered a form of contribution — but not necessarily the other way around. So that argument would suggest "contributor" is the better term.
However, I feel the argument that the term reviewer will make ThinkLab more approachable and understandable for new users trumps the other argument.
At the end of the day this is something we'll be able to easily change in the future so it's really not that big of a deal.