Most people do not realize there are two basic ways in which tests are scored. The scores on some tests are "norm referenced". On those tests the scores of all participants are ranked by number of correct answers. Then the bell curve is superimposed on those scores. In doing this a specific percentage of test takers are given very low scores, average scores and very high scores. These scores are called standard scores since they depend on the test standards that are pre-established. So let's say a person takes a test with a group of other test takers, all of whom are VERY good at what the test is testing. Under the norm referenced system, an individual who missed very few questions could still get a low score because in comparison to the other testers in the group, she was at the bottom of the pile. Most college entrance exams such as the SAT and the ACT are norm referenced. The idea is supposed to be that colleges are interested in how applicants rank in comparison to other high school grads who are seeking entrance. Most achievement tests and aptitude tests are also norm referenced.
Criterion referenced tests establish skills and knowledge that test takers are supposed to know. Then test takers are scored on how many questions they answer correctly. Under this system it is possible for every test taker to get a high score. These tests do not give you the relative standing of one test taker against another. The Common Core tests and tests created by teachers are generally considered to be criterion referenced tests. Common Core tests are supposed to be measuring how much of the Common Core curriculum a child has learned. Whether they do that or not is an issue for another day. On criterion referenced tests we are all rooting for all the test takers to score well. The high score of one student does not impact the chance of another student getting an equally high score. On the norm referenced tests, all students cannot do well no matter how many questions they answered correctly. It is the nature of the beast.
On norm referenced tests we are competing against each other; so if you answer one more question correctly than I do, your higher number correct could kick me lower down on the bell curve.
Both kinds of tests have their purposes and do different things. Of course, neither addresses the over all question of do tests really matter at all. What does either type of test tell us that we didn't know to begin with. When I was a public school supervisor, I would frequently have teachers tell me that they knew in advance exactly which students would do well on a test and which would not. When I asked the question, then why are you bothering to test at all?; I would get a quizzical look. I am still asking that question and still getting that same quizzical look.