, surveys are a poor instrument for evaluating the efficacy or quality of courses. Much of what students do, think, & feel while they are studying is not available to consciousness & students also tend to have great difficulty in remembering the details of their studying experiences, which makes sense - they're supposed to remember the course content & learning objectives more than anything! The best way to evaluate that is well-designed & frequent testing, which also has benefits for learning (See Roediger & Karpicke's "testing effect" AKA, "retrieval practice") & if you can, regular classroom &/or online observation, because a knowledgeable independent observer can perceive far more of what is actually going on during a classroom than the teacher or students can.
Additionally, there are ethical issues with student teacher evaluations, i.e. they tend to elicit students' gender, ethnic, & race prejudices (Please see here: https://3starlearningexperiences.wordpress.com/2017/02/07/student-teacher-ratings-males-are-brilliant-females-are-bossy/
If you're genuinely motivated to improving the quality of students' learning experiences, it's essential to choose the most appropriate instruments to collect that data that answers the questions you're asking of it.
Just my €0.02!