One of the biggest mistakes being made by public school administrators and politicians is the push to pressure educators to "teach to the test". NCLB fully embraces this simplistic and one-dimensional method of educational assessment. However, there are far too many important aspects of learning and cognitive growth -- hands-on laboratory techniques and skills, data processing and analysis, deductive reasoning and analytical thinking -- that do not lend themselves to assessment via these types of standardized multiple choice tests.
In addition, these tests are often administered one to two months before the end of the school year, yet they are designed to evaluate student achievement and conceptual understanding of the entire year's curriculum in that subject area. So teachers are being pressured to restructure the curricular content, eliminating or postponing until late in the school year coverage of those skills and topics that are not emphasized on the standardized test.
But politicians (and many administrators) love simple, objective measuring sticks -- even if what they measure has little value. So we invest millions of taxpayer dollars and valuable days of instructional time administering these tests to students, and essential judgements about the quality of education and critical decisions regarding educational practice and policy -- including school funding, county and state-level punitive measures, teacher evaluations, and merit-based pay -- are made based on this single metric.