For NSF proposal and grant purposes, do graduate students meet the definition of "investigator"? I recently received an email from a department administrator that NSF rules have been changed (link here), such that all investigators must fill out a conflict of interest (COI) form.  They then go on to list a cadre of examples which meet the definition of investigator and a statement that all investigators must fill out this form.  Our university has the definition of investigator here.

My question is, are graduate students typically considered investigators by the NSF?  If so, we certainly do not receive the recognition that PIs and other listed investigators get.
Actually, the NSF, in its Grant Proposal Guide, does not actually define the concept of an "investigator." Instead, it chooses to define the different categories as "senior personnel" and "other personnel." Typically, postdoctoral fellows and graduate students fall under "other personnel." 

Personally, in such matters, I would opt on the side of caution and just have the graduate students fill out the conflict of interest form. It doesn't take very long, and having it in place makes life easier for everyone.