Who May Serve as PI:For REU Site proposals, a single individual maybe designated as the Principal Investigator. This individual will be responsible for overseeing all aspects of the award. However, one additional person may be designated as Co-Principal Investigator if developing and operating the REU Site would involve such shared responsibility.After a proposal is awarded,some NSF units may allow the addition of more Co-PIs if an exceptional case can be made for why the management of the REU Site must be distributed.