Most basically, a school that frequently teaches useful-but-not-tested material will, all else being equal, produce lower test scores than a school that sticks rigidly to the tested material.
I'm not sure this is "gaming", proper; but if this focus on the tested material prevents a teacher from enthusiastically expounding on something (s)he thinks is especially fascinating, I'd count that as a loss. Because having enthusiastic teachers is great.
(Of course, standardized testing has benefits, too - I'm not sufficiently informed on American education to have an overall opinion. I just wanted to point out that there are ways to test better that don't improve education.)
If a teacher enthusiastically expounds upon football, string theory or creationism, and fails to teach reading comprehension, they will indeed suffer on the tests.
This doesn't seem like a bad thing. Deciding what needs to be taught is the job of the political system, not the teachers.
Ignoring the obvious hyperbole of your first sentence, sure politics essentially sets the curriculum (for better or for worse). That doesn't excuse the political system also getting in the way of teaching it.
Mercifully in Australia we don't have standardized testing every year (yet), but enough importance is tied to the tests that do take place that a disproportionate amount of time is spent preparing kids for the style of tests administered, regardless of any gaming of the system, reducing the time spent on the rest of the curriculum.
I know we've argued education before and so I'm not expecting a hallelujah moment, but I figured it was a point that should also be made.
Policymakers decided that kids should be taught a variety of subjects - state graduation requirements include science, social studies, arts and languages. However, standardized testing focuses on math and language arts. So you have the phenomenon of art teachers or history teachers being ordered to teach math or reading in order to boost test scores.
The math and reading requirements are hardly unreachable. If history teachers are trying to teach history to students who can hardly read, they're not going to get very far. They should push back against the language arts teachers to do their jobs.
Probably not (I'm not opposed to standardized tests, FWIW). Schools need to teach art in art class, history in history class, &c. If lying about curricula to squeeze in more test prep doesn't count as "cheating", it's hard to imagine what could.
...and restricting what is taught to what can be measured is a bad idea. As is putting so much emphasis on your measurements (and little enough work into creating them) that teachers have an incentive to teach the content on the test rather than the full breadth of the subject.
Most of my math classes growing up ended with a week or two of "here's how what you just learned applies in the real world / future classes". It was one of the few redeeming aspects of my early math education, and is probably one of the first things to get cut when schools want to beef up test scores.
If a maths teacher wants to teach category theory, or algorithmic analysis (things which can be both interesting and relevant to a someone growing up), they can't.
The state legislature and federal government have decided that arithmetic is more useful than category theory. I agree with them completely, and I'm one of those rare people who is extremely sympathetic to category theory.
So yes, I think tests are doing the right thing here - making sure the teacher does his job before he goes off on random tangents.
I'm not sure this is "gaming", proper; but if this focus on the tested material prevents a teacher from enthusiastically expounding on something (s)he thinks is especially fascinating, I'd count that as a loss. Because having enthusiastic teachers is great.
(Of course, standardized testing has benefits, too - I'm not sufficiently informed on American education to have an overall opinion. I just wanted to point out that there are ways to test better that don't improve education.)