Personally I always ask for lecture/presentation slides - it's common practice in computing and related fields. Technical conferences (be they industry-focused like Nvidia GTC or more research-focused like Usenix ATC) routinely provide presentation slides and recordings. Both are extremely valuable.
I understand that a professor may dream of lectures passing through students' brains before being recorded in high-quality, personalized notes. The reality is that lectures are easier to follow when you aren't frantically trying to copy down the lecture slides as well as what the instructor is saying (after all, it might be on the exam!)
Presentation slides are valuable instructional materials, and withholding them is unlikely to improve learning. In my experience, the best lecture-based courses (in science/math/engineering at least) provide material in at least three ways: in the textbook or readings, in the spoken lectures, and in presentation slides or provided lecture notes – with reinforcement and active learning via problem sets, labs, and/or projects. Interactive review sessions, discussion sections, and tutorials can also help.
I understand that a professor may dream of lectures passing through students' brains before being recorded in high-quality, personalized notes. The reality is that lectures are easier to follow when you aren't frantically trying to copy down the lecture slides as well as what the instructor is saying (after all, it might be on the exam!)
Presentation slides are valuable instructional materials, and withholding them is unlikely to improve learning. In my experience, the best lecture-based courses (in science/math/engineering at least) provide material in at least three ways: in the textbook or readings, in the spoken lectures, and in presentation slides or provided lecture notes – with reinforcement and active learning via problem sets, labs, and/or projects. Interactive review sessions, discussion sections, and tutorials can also help.