Photo: 68/Corbis

On a snowy morning in January, on the repurposed second floor of a cavernous parochial school, the 135 sixth graders of Leaf, a brand-new charter middle school in Brooklyn, are getting ready for the first of six full school days of testing. (I’ve chosen a pseudonym for this school and its students, administrators, and teachers to ensure that they can speak freely.) The students aren’t taking the real New York State standardized tests, which come in April, nor are they taking the extra benchmark exams that are up to each school to choose for their own diagnostic purposes. Leaf does those in reading, social studies, science, and math in August, December, and June — seven testing weeks a year out of thirty-six, a pretty typical schedule.

Instead, today is the English Language Arts (ELA) Mock Exam: three days spent taking a practice reading test, to be followed by the Math Mock Exam next week. Regular students will take the test for ninety minutes each morning; the one-fifth of the students who have a learning disability, English language learners, or ADD (Attention Deficit Disorder) diagnosis get double time, up to three hours to complete the test. In the afternoon the kids are “burnt,” said Ms. Berry, the principal, both from the questions and from sitting in total and strictly enforced silence for three hours. So they’ll spend the rest of each day doing meditation, playing games in the gym, drawing pictures, and watching movies.

It’s a big investment of time and resources, and the results count for nothing. But Ms. Berry knows from experience that a top-to-bottom dress rehearsal is necessary in order to calm nerves and deal with any logistical issues that might come up before the big days. As we walk the halls the troubleshooting begins: one kid finished the first section in pen, which is verboten. A teacher has a cup of coffee; if a monitor dropped by from the city, that would be considered an infraction of the strict rules for proctors. In another classroom an inexperienced teacher needs a pep talk; she’s unable to control her students’ multiple requests to move their desks around the room “to concentrate.”

The word of the day is anxiety. Parents are anxious about how their students’ scores — one for “below standard,” two for “basic,” three for “proficient,” and four for “exceeds proficient” — will look on their applications for competitive public high schools. They call to complain that Leaf is doing either too much test prep or too little. Some New York City public schools send home workbooks for months on end; others hold Saturday tutoring sessions every week of the year. Despite the six days of mock testing, Leaf is actually on the lighter end of the spectrum.

Teachers are anxious because 40 percent of their evaluations come from student scores on a combination of state and other standardized assessments. Ms. Berry is anxious because under New York City’s charter school rules, if they don’t demonstrate enough test score growth within each subgroup of minorities, English language learners, and learning disabled students, they’ll be closed in five years.

Students pick up on their parents’ and teachers’ anxiety. Some stay home with stomachaches. Others stare into space or misbehave. “My mom worries about me a lot. So does my grandmother,” says Lucas, a liquid-eyed sixth grader carrying a fantasy novel with a dragon on the front. When I ask what he thinks of the test, he says, “It’s like a life-and-death situation. It decides whether you’ll get to another grade. If not, people will be disappointed with you.”

Leaf isn’t the only school in the country that’s consumed by anxiety over standardized testing. It’s close to the norm. And as students, family, and school leaders scramble to comply with these requirements, sometimes they lose sight of the big picture: there’s lots of evidence that these tests are doing harm, and very little in their favor.

In the first chapter of my book, The Test: Why Our Schools Are Obsessed with Standardized Testing — But You Don’t Have to Be, I explore 10 arguments against high-stakes standardized tests, as currently administered annually at Leaf and nearly every other public school in the nation. Here, I’ll focus on just one: We’re testing the wrong things. States are required to test just two subjects: math and language. Reading is emphasized over writing because the tests are mainly multiple choice.

Hugh Burkhardt is a British mathematician and international expert in both curricular design and assessment of mathematics. He has been a consultant on the development of the new Common Core tests. In his spare time he dabbles in elementary particle physics. When I ask him about the problems with tests as they are currently used in the United States, Burkhardt puts it this way, in a plummy accent: “Measurement error consists of two parts: systematic and statistical error. The systematic error in education is not measuring what you want to measure. … Psychometricians [test makers], who usually focus only on statistical error, grossly overestimate the precision of tests. … They just assess some bits that are easy to assess accurately.”

In other words, to use a metaphor: if your telescope is out of focus, your problem is a statistical error. In Burkhardt’s opinion the lenses we’re using are sharp enough, but we are focusing on just a few stars at the expense of the universe of knowledge.

Are we measuring what we really want to measure in education? A flood of recent research has supported the idea that creative problem solving, oral and written communication skills, and critical thinking, plus social and emotional factors, including grit, motivation, and the ability to collaborate, are just as important in determining success as traditional academics. All of these are largely outside the scope of most standardized tests, including the new Common Core–aligned tests.

Scores on state tests do not correlate with students’ ability to think. In December 2013 MIT neuroscientists working with education researchers at Harvard and Brown Universities released a study of nearly 1,400 eighth graders in the Boston public school system. The researchers administered tests of the students’ fluid intelligence, or their ability to apply reasoning in novel situations, comprising skills like working memory capacity, speed of information processing, and the ability to solve abstract problems. By contrast, standardized tests mostly test crystallized intelligence, or the application of memorized routines to familiar problems. The researchers found that even the schools that did a good job raising students’ math scores on standardized tests showed almost no influence over the same students’ fluid intelligence.

Daniel Koretz, the Henry Lee Shattuck Professor of Education at the Harvard Graduate School of Education and an expert in educational testing, writes in Measuring Up: What Educational Testing Really Tells Us:

These tests can measure only a subset of the goals of education. Some goals, such as the motivation to learn, the inclination to apply school learning to real situations, the ability to work in groups, and some kinds of complex problem solving, are not very amenable to large-scale standardized testing. Others can be tested, but are not considered a high enough priority to invest the time and resources required … even in assessing the goals that we decide to measure and that can be measured well, tests are generally very small samples of behavior that we use to make estimates of students’ mastery of very large domains of knowledge and skill.

So some important things we don’t test because the tests aren’t up to it. Some we could test but don’t bother. And for the things we do test, the tests are actually too small a sample of behavior to make wide-ranging judgments.

From The Test: Why Our Schools Are Obsessed with Standardized Testing — But You Don’t Have to Be by Anya Kamenetz. Excerpted by permission from PublicAffairs Books, an imprint of the Perseus Books Group. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.