For example: during our standardized testing this year, the school put in huge amounts of effort to align student incentives, most of which were silly and clearly ineffective. (My personal favorite? Disallowing students to bring their own books to read after they finished the test to "encourage" them to check their work instead of hurrying through so they could read the next chapter of The Hunger Games. Talk about easy ways to incite student frustration and contempt!)
I can attest to students finishing a test in less than 10 minutes despite being given more than an hour, or refusing to do any of the test at all. I've heard horror stories of students using the multiple-choice answer documents to make pictures by filling in the bubbles, or simply choosing to color in bubbles so lightly that they can't possibly be read. I know of examples in prior years wherein students chose to write essays about how much they hate testing on the essay portion instead of addressing the infantile tripe they were assigned.
Now, these are obviously exceptions to the rule (I'm a bit biased, but I think our students are almost uniformly excellent), but it is amazing how much damage one student can do by choosing not to care. (Or, in some cases, using their answers to vent their frustration).
And why should they? As far as I know, rewarding students for higher performance is disallowed, leaving teachers with very few tools with which to convince students that these tests matter. Sure, you can go on and on about how their scores will be "important" in their future (which, to my knowledge, isn't always true), but that only goes so far. Sometime during the 2 weeks of intensive testing, the kids just don't care anymore.
I'm all for assessing the performance of teachers, and I'm not sure how to fix the problem (or even if it can be fixed), but one thing seems clear to me: they're doing it wrong.
[Updated to fix punctuation errors]