There are many aspects of this new high-stakes test-based system of accountability which I deTest. Test prep wastes good classroom time and lots of it. Some teachers may be provoked to go to great lengths to show student growth in order to protect their professional lives.
Moreover, teachers are increasingly asked to give pretests by which end-of-the-year progress may be measured. Testing eats up more and more time. When pretests are given, students are either tested on stuff they've never learned (which is ridiculous) or teachers may be martyred (see comment by tiredteacher).
Teachers will be encouraged to grade hard in September and then ease up in June. There is an incentive to score students low at the start of the year so that progress can be guaranteed by June. It is all one great, big game which eats at the heart of why most people became teachers. It is not to play a game of statistics to artificially pump out a sometimes misguided definition of success.
We see success engineered, albeit slowly, on the Common Core tests. Cut scores are manipulated to show slight improvements in student performance. The Common Core must be working. I've seen some pretty screwy assessments in reading levels as well, children starting the next academic year a couple of levels below their level calculated the previous June. And, we are supposed to believe that all of the metrics show a mathematical precision!
I opt instead for a world in which testing has a purpose to help teachers learn how to better help students. I opt for a world in which there are few, if any, high-stakes tests involved. I opt for a world in which teachers are trusted to test their students on what they taught and assess student growth without standing to gain or lose anything more than the satisfaction earned by helping a kid achieve a worthy goal. I hardly recognize the profession I entered over twenty years ago any more.