Matt Yglesias writes that there is no contradiction between a rich curriculum and standardized testing. This is true. But there very well might be a contradiction between a rich curriculum and accountability tied to student standardized test scores. There is overwhelming evidence that when school funding and teacher/principal evaluation and pay are tied to scores on such exams, incidences of teaching-to-the-test, curriculum-narrowing, and even outright cheating and fraud go up.
Consider the example Matt and I have discussed, on the benefits of reading and reciting poetry. After NCLB was instituted and third through eighth graders across the country were required to be tested annually in reading and math, ace education reporter Linda Perlstein wrote Tested, about a Maryland third-grade classroom struggling to achieve proficiency. Here's how poetry was taught to those students:
The third-grade teacher I followed for my book Tested had a good sense of what was going to be on the Maryland School Assessment. The exam, and the benchmark tests designed in its image, didn’t change a whole lot from year to year—there were certain constructs that showed up again and again, and certain questions too. One question she’d come to expect was, “How do you know such-and-such is a poem?” The standard tested was identifying the elements of a poem. We all know that the best way to ingrain an enduring understanding of poetry is to have students not just read poems but to engage with them—especially, to write them. These kids didn’t do that. More than 30 times the teacher had the kids copy some form of this paragraph from the overhead projector: I know this is a poem because it has rhyme, stanzas and rhythm. It has rhyme because sea and free rhyme. It has stanzas because the paragraphs don’t indent. It has rhythm because...
This is bad instruction informed by test-based accountability. Opposing such accoutnability policies doesn't necessarily mean that one in anti-test; rather, it's important to note that the preferable use of tests is to diagnose the strengths and weaknesses of individual students, so as to better target instruction toward them. When testing policies are set up to punish adults, educators are incentivized to raise test scores at any cost, not to use tests to help better instruct children.
If you want to learn more about the history, uses, and limitations of testing, please pick up Measuring Up: What Educational Testing Really Tells Us, by Daniel Koretz.