TABLE 1.

Reported advisor motivations for supervising undergraduate researchers

Intrinsic category	Example	Instrumental category	Example
Development of the scientific workforce (18 advisors, 31 comments)	Education is important … I feel strongly about being part of a university community.… I think it’s an important contribution.—Female postdoc, #22	Increased lab productivity (11 advisors, 18 comments)	The most important thing is that they just get experiments done, or they help. It’s a lot of the labor that no one wants to do.—Male faculty, #13
Wanting to serve as a mentor (7 advisors, 9 comments)	I was really excited to start mentoring an undergraduate because I really enjoy it … helping them learn all these different aspects.—Female graduate student, #7	Requirement of PI (6 advisors, 8 comments)	[My PI] basically will assign like grad students in the lab to mentor them.—Male graduate student, #24
Undergraduates make lab work more fun (1 advisor, 1 comment)	It’s fun…. You need that.… You can’t be just 9 to 5 talking about mutations.—Female faculty, #21	Requirement of job or position (3 advisors, 3 comments)	In my lab, the technician oversees all of the undergraduate researchers, so it was part of my job.—Female technician, #26
		Helps check work (1 advisor, 1 comment)	I had a massive amount of things that needed to be checked again.… She can learn and help [me] out by checking [my] own work.—Male graduate student, #4