Applying for a graduate research position can seem daunting. Especially when you are an undergraduate student and have little inside-look into how a research lab operates. This a quick look into the members of a typical lab and their roles:
Principal Investigator (aka, P.I., supervisor, professor): they are the lead scientist of the lab who holds the grant (money to run the lab) and the lab bears their name (for example, Stephen Hawking lab/group). They are, at most times, affiliated with a university and you would have met them as ‘professors’ in undergraduate or graduate courses. They have been recruited by the institution to run their own lab having shown their competence in scientific research (publications) and other track records. They conceptualize the research projects and are the overseer of all the projects and members of the lab.
Research Associate: as the right-hand of the PI, they often take care of the logistics of the labs and assist in application for the grant. Their involvement in actual experiments vary from lab to lab. They have extensive experience in research, and usually holds a PhD or was Post-doctoral fellow before getting recruited to a lab.
Research Assistant: they are hands-on assisting other members of the lab with experiments. They are most often the member of the lab who can best help you troubleshoot with technical aspect of the experiment when you are new. They usually hold Masters or PhD degree and is recruited to the lab.
Post-doctoral fellow (aka, post-doc): they create their own research project with P.I.s, runs experiments, applies to grants, and oversees projects of PhD and Masters students. They are a PhD graduates who are aspiring to be a P.I. (the route to the PI position often looks like this: Undergraduate – Masters, PhD, PhD/MD – Post Doctoral – P.I.). They will likely be the person PhD an discuss about your project in depth on a day-to-day basis as a graduate student. Depending on the administrative or clinical position, P.I.s may not be accessible to discuss the project as frequently. You are likely to run the project with a post-doc who has been assigned to you and discuss the results with your PI on a more regular occasions.
PhD and Masters: they often receive their research project from P.I. and run their own experiments. They are usually the main personnel of the lab running the experiments along with post-docs.
Undergraduate: they undertake a smaller project or a part of a larger project to fulfill an honors degree requirement or as an intern.