I studied EE. I’m familiar with the curriculum, various textbooks in the field, and the difficulty of topics. Google the curricula of some core courses at any school and you can easily get an idea of the rigor of the school. Most schools publish their curricula so that employers and graduate schools who are unfamiliar can evaluate the program. This is what graduate schools to evaluate universities they are not familiar with. Obviously, the graduate committee has not taken exams at every university (-;. My evaluation was obviously fairly coarse-grained.
People make evaluations about things they are unfamiliar with all the time. I interview candidates and have to screen through resumes. To deal with possible bias and imperfection of evaluations, candidates usually go through multiple rounds of interviews.
It’s really simple. Hope that answers your questions.