The Principal Investigator (PI) or Project Director (PD), Participating Investigators, Senior/Key personnel (as identified by the institution in a proposal or sponsor report), and any other individual identified by the PI/PD as responsible for the design, conduct, or reporting of the research (i.e., not simply working on or engaged in the project). This includes administrative and programmatic aspect sof a project.
There is also a Sponsor PI. If an employee or student of the University of Michigan does meet the eligibility requirements for the sponsor but not for the requirements of U-M, they are named on applications as Sponsor PI (e.g., students or fellows). See: Definition of Principal Investigator.