I just received my summary statement for an R15 I submitted in October and found out that I had four reviewers score my proposal. I thought that three reviewers was routine. Would anyone know why a fourth was included?
Thanks for your help.
I had the following response, slightly expanded for this context.
Any member of the panel can review any proposal (save conflicts) assigned to that panel and write a critique if they so choose. In theory you could end up with 20 or more of them!
Of course this never happens. Although I will say that it seems to me that the chances of picking up extra reviews is enhanced when your application is reviewed in a tiny Special Emphasis Panel convened to cover just a handful of applications. (I think I've had a 5-reviewer summary statement as my high water mark.)
What I have seen occur at a normal study section meeting is that someone not assigned to the application will get really involved in some point of discussion (pro or con, people, pro OR con). The system recognizes that the summary statement is supposed to reflect the discussion. Revision of the critique to more accurately depict the discussion is highly encouraged.
So sometimes the SRO or Chair or a panel member will say "Hey, will you 1) write that up as a critique; 2) write up a brief blurb for the SRO to include when prepping the resume or 3) write up a point for one of the other reviewers to include when they are editing their review?"
Or, occasionally, a reviewer will just be so ticked about where the assigned reviewers and panel votes went that s/he will just write up a dissenting view on his/her own hook. I'd suggest that if you see a fourth, highly disparate review, perhaps focused on a single issue, that you recognize that this probably had very little effect on your score... Nice to get the warm fuzzies if the outlier loved your proposal, I suppose.
One final scenario may also be at work. The way I understand it* the official rules require that at least two people assigned to the application have to be in the room if it is to be discussed. So if for some reason 2 of the 3 are phone reviewers, the SRO may tap a 4th "discussant" reviewer to fulfill this requirement.
*it is possible that this is only a strongly encouraged practice and/or a practice limited to selected study sections. I'm not easily finding instructions-to-SROs on the CSR website.