Gary Thomas said this quote
“ One of the most significant consequences of the proliferation of tests over the last decades of the 20th century and the first of the 21th has been this tendency of assessment to direct the curriculum. Like a huge magnet, assessment drags curriculum toward it. It should, of course, even if we accept the need for tests, be the other way round: the curriculum should be shaped independent of any consideration of tests: tests should be constructed and administered in another space, both literally and metaphorically, hermetically sealed not only form the teacher’s gaze but also – and even more importantly – from the teacher’s consideration. In practice, though, this never happens. It is inevitable that if you decide regularly to test children's performance on the curriculum, and if, furthermore, you make teacher’s careers and school’s futures depend on the result, the tests will very quickly come to dominate what is taught. Not only the content, but also the style and manner of the teaching will be influenced by the tests. Teaching will be about getting the right answer, irrespective of understanding. ”