There are real issues with using class size as they do. If you have someone that's really good at teaching a particular class, it's better to have them teach one section of 60 students rather than have a second section taught by someone that does a mediocre job. You also have things like TA help for larger classes, and that doesn't factor in at all. There's also the discontinuity thing. 30 is way better than 31, but equally better vs 300 - which obviously makes no sense. Overall, the measures they use for class size in these rankings are garbage.
The same is true for selectivity. It doesn't account for education at all, only the difficulty of getting in. But since it doesn't account for the applicant pool, it doesn't account for the difficulty of getting in either. You could use things like SAT scores as a measure of the difficulty of getting in and ditch the acceptance % completely. I work at an R1 that gets hit hard because we admit most applicants because, you know, we exist to educate folks, not to serve as a signalling device.
The same is true for selectivity. It doesn't account for education at all, only the difficulty of getting in. But since it doesn't account for the applicant pool, it doesn't account for the difficulty of getting in either. You could use things like SAT scores as a measure of the difficulty of getting in and ditch the acceptance % completely. I work at an R1 that gets hit hard because we admit most applicants because, you know, we exist to educate folks, not to serve as a signalling device.