Understanding an advisor’s refusal of an internship I am graduate research assistant in Computer Science in the US. A while ago, a master student in the research group, who plans on a career in industry after graduate school, received an internship offer from a large, well-known technology company which is one of the most sought after and prestigious opportunities for any computer-science student. An internship at a company such as this would be extremely valuable both in terms of shining on his resume and the experience he would gain there. This internship would be a huge break for him and could really launch his career.

However, when he asked for his advisor’s okay to take the internship for the summer, his advisor told the him that he would have to find someone to replace him to continue work on the research project which would essentially mean the student would lose his funding when he returned from his internship.

My question regarding this is:

What are the pros and cons a professor has to consider when deciding upon allowing his student to do such an internship, particularly regarding that such an internship would be tremendously valuable to the student’s career?
If you consider the Master's assistant position from the perspective of a paid job, it would be unreasonable to expect an employer to grant what essentially amounts to a sabbatical. Professors and school teachers are often given sabbatical leave, but Master's students are in a very temporary position. It's not a common thing, and there are no long-term benefits to the employer to outweigh the inconvenience.

If it is feasible to do so within the bounds of the research project, then it would certainly be reasonable for the professor to grant the student's request. But I don't see that the professor has an ethical obligation to do so.

Funded research is commonly held to tight deadlines – once the timeline of a project has finished, any unspent money usually returns to the funding organization.

If the professor could do so, without a negative impact on the research, I am sure that any reasonable person would grant the request for leave. The simple answer is that it's quite likely that he or she simply cannot feasibly put the research "on hold".