Ways to tell interviewers you want some time to think about your decision (Employment in Academia) I am interviewing for employment in academic labs as a computer scientist, one of which a childhood friend is in and has some position of seniority. According to my friend who has spoken with the PI on the spot, the PI loves my letters of recommendation, my CV, my cover letter, etc. and the PI is willing to offer me the position on the spot if I don't screw up the interview. However, I am still wishing to keep my options open as there are other labs who have given me interviews during the same week as my interview with this current lab. How do I politely tell the PI I want some time to think about it? There are other factors that I want to weigh in like money, relative interest in the projects, my perceived contribution/role, etc.
Usually, no one expects you to respond to an offer on the spot.

An important distinction to make is that the PI may offer you a verbal offer on the spot but generally it takes some time to get the formal offer. Accepting the verbal offer does not necessarily mean you have the job.

If the PI gives you a verbal offer, then just respond with a compliment (e.g., "Thank you, I am very impressed with your lab") and then ask when to expect the formal offer and when you should respond by.