Why do colleges require/recommend Subject tests?

If you are an AP student, and your grades show you are proficient in the subject, why do you need to take them? If people are confused by what I’m saying, here’s an example. You are in AP chemistry, you have an A in this class and got a 4/5 on the AP and you got an A in regular chemistry. Does it really benefit you to take the SAT subject test on chemistry even though you’ve proven yourself?

@UNC115 Well what if you aren’t an AP student? Or if your school doesn’t offer AP/IB subjects?

Some schools recommend or require SAT subject tests as a means of standardization, as well as to verify that you are qualified in areas that the regular SAT or ACT doesn’t verify.

@MITer94 I understand that not everyone is an AP/IB student. But for my example, are Subject tests really beneficial, or are they just another thing to put on college apps?

Unfortunately, colleges have different ways that they want you to prove yourself. Certain colleges require Subject Tests from all applicants or recommend them to applicants. AP’s are not a substitute for the “required” group.
http://www.■■■■■■■■■■■■■■■/subject-test-requirements-and-recommendations/

Would a Chemistry Subject Test in your specific case improve a college’s understanding of your chemistry knowledge? Probably not. But you don’t want to find yourself applying to MIT and realizing at the last minute that you didn’t take a required Subject Test.

Let’s get some semantics out of the way. If you get a 5 on an AP exam, you are not “proficient” in the subject, regardless of what the subject is. You have simply demonstrated skill of that level of the subject.

Anyway, it is what it is. The college wants what it wants.