I've been on a couple of research projects with a few professors and have had some success recently and plan to do more collaborative work through the end of this calendar year. One student is constantly leeching off of me and imposing himself, such as wanting specifics about my work, specifics about private meetings between me and my research advisors, wanting to come to lab while I am there to do some work. (he is not part of the lab.) How do I tell this person to back off and do his own work, establish his own connections and stop creeping on me and stalking my every move in hopes of leapfrogging me, just because I've had some recent success? Do I have to continually say, "this is private and ongoing research that isn't published yet"?
Your time is yours to control. If someone just wants to meet to learn about your field, it's polite etiquette to give them a brief meeting and let them learn... it is a learning environment, after all. It sounds like your situation has progressed well beyond that. I would simply tell the student that due to your own time constraints you cannot continue meeting with him. Consider redirecting him to the department chair/administrators, where he can ask about the process for joining a lab.
For what it's worth, if it's really beyond academic interest and he's just a stalker, that changes things a bit. Definitely work with whatever resources your university makes available to figure out how to deal with a stalker.
You seem to assume the worst case scenario. The student may be genuinely admiring you. It is common in the industry to shadow someone for training purposes and the person may be assuming it is ok here as well. Also, some people are bad at picking cues, so he may be oblivious to your discomfort. Or even worse - painfully aware, but feeling he deserves such a treatment because of his lowly status.
Now, you of course have every right to not wish to mentor this person in any way. So I would suggest to be open but also generous with him. At the end of the day, you may need his help later, so it won't hurt to be nice now.
- Select a time to address this issue in private in a separate meeting. For example, invite to have a lunch or coffee together.
- Summarize the problem in neutral terms
- Acknowledge his good intentions (even if you believe otherwise). Sth like "I appreciate you want to learn how to be a good researcher and it is flattering that you think I am one".
- Give an objective (preferably external) reason that has nothing to do with him personally. For example, by letting him into the lab/sharing details of private meetings you are violating a policy and can face repercussions. Or your supervisor doesn't appreciate external people in the lab or meetings. Or, as much as you enjoy his company, you really can only focus when you are alone. Don't invent a reason though.
- Offer a practical alternative. "I actually think you will learn most by doing A, B, C rather than shadowing". A, B, C can be a book that you read at some point that really illuminated you. Or some best case practice of being a good researcher. Or perhaps you don't mind having a monthly "mentoring" meetings with him. Maybe he has a specific weakness or an under-leveraged strength, and you can advise on to how to work on those. Whatever lifehack you feel comfortable sharing and that can genuinely help the other person.
This is a companion answer to the one written by @olgak. First, quoting Olga:
The student may be genuinely admiring you. It is common in industry to shadow someone for training purposes, and the person may be assuming it is ok here as well. Also, some people are bad at picking cues, so he may be oblivious to your discomfort. Or even worse - painfully aware, but feeling he deserves such a treatment because of his lowly status.
This is very insightful. But where I differ from Olga's suggestions is that to my mind, she's neglecting to consider the role your advisor or P.I. can play in addressing the problem. So here's my slightly different answer:
You can, optionally, try, once, to get some more distance with this eager beaver, hopefully without bringing offense (the flavor of Olga's suggestions is great for this).
If that doesn't work, or if you don't want to play that role, let your primary advising or collaborating professor know that you are uncomfortable. Don't make it sound like a complaint yet (reserve that for the future, if this first step doesn't work), and try to give the eager beaver the benefit of the doubt in your description. Your main message needs to be be
(explicitly) In his/her eagerness, J. Student has been asking me lots of questions about my research, and I'm uncomfortable and unsure how to handle it.
(implicitly, i.e. I doubt you'll need to say this out loud) Can you handle this for me, please?