Which undergraduate research experience will help more for graduate admissions in mathematics? I was recently offered a six-month undergraduate thesis at two places. Let us call them A and B. 

I am looking to apply abroad for my Masters in pure math next year. Hence, recommendations are important to me.  I am not sure which offer will yield a more useful recommendation.

The professors who have accepted me at A and B are both the leading experts in my field of interest (Algebraic Geometry), and have won the highest honour given for Mathematics in my country. The professor at B seems vey encouraging and helpful, and has found the time to go through my math blog and offer feedback, while the professor at A has a reputation for being abstruse, and hence perhaps not ideal for a person not experienced in research. However, A is a much more reputed and well known school than B. 

Should I go to A or B? 

Will a recommendation from a well-known professor from a less well known school matter as much as one from a well known professor from a well known school? 

Should my personal equation with the professor be the most important factor for me?
I understand your question as: Which will be more useful for graduate admissions (all other things being equal): a recommendation from a professor at a well-known university, or a recommendation from a professor at a less-known university with whom I have a more personal connection?

There is no one-size-fits-all answer here. The answer depends quite a lot on the degree of the difference (both the difference in reputation between universities, and the difference in how well each professor will end up knowing you personally).

As you have intuited, a recommendation from someone at a well-known institution is worth a lot more than a recommendation from someone at an institution that is not well known. On the other hand, a recommendation that describes your specific talents at mathematics in complimentary detail is worth a lot more than a perfunctory letter that says "Algebraically speaking did a thesis in my institution."  (Meanwhile, you know nothing at all about the letter-writing skill of either professor, which is another important variable.)

There is also the impact on your development as a researcher. You would likely benefit from working with someone who takes a close personal interest in you. You would also likely benefit from being at a well-known institution that attracts many talented students and has a very productive research atmosphere.

Your decision will ultimately be a personal one, and we can't give personal advice on Academia.SE. However, since your goal is to go to graduate school abroad, I would suggest the following:

Find out where undergraduate students who work with each professor end up.

You can ask them directly, or talk to their students. In either case, you'd like to know:


how many of their undergraduate students want to go on to graduate school in mathematics? How many of these actually do?
for the students that went to graduate school, where did they go? Are these institutions you would consider attending for graduate school?


The "road less traveled" can be great, and rewarding, and all that. But it's also more difficult. If there is a well-traveled path that leads to your desired outcome, get on that path if you can.