Gianni Dagli Orti/The Art Archive at Art Resource, NY

Educators, policy makers and business leaders often fret about the state of math education,” the New York Times reported in May. “But reading comprehension may be a larger stumbling block.” Indeed, schools and teachers consistently have better luck improving student skills in math than in reading. A fresh reminder of the difficulty came in August, when New York released scores from its first round of tests aligned with the Common Core State Standards, now adopted by most states. Students in schools across the state fared poorly on the tests; some of the city’s most celebrated charter schools posted disappointing results as well. The silver lining is that by adopting reading curricula aligned with the Common Core and abandoning failed approaches to literacy instruction, New York City could be poised to lead a reading renaissance in the coming years—but only if city schools also make significant shifts in classroom instruction and exercise patience.

Math is relentlessly hierarchical—you can’t understand multiplication, for example, if you don’t understand addition. Reading is mercilessly cumulative. Virtually everything a child sees and hears, in and out of school, contributes to his vocabulary and language proficiency. A child growing up in a book-filled home with articulate, educated parents who fill his early years with reading, travel, museum visits, and other forms of enrichment arrives at school with enormous advantages in knowledge and vocabulary. When schools fail to address gaps in knowledge and language, the deficits widen—a phenomenon that cognitive scientist Keith Stanovich calls the “Matthew Effect,” after a passage in the Gospel of Matthew: “For unto every one that hath shall be given, and he shall have abundance: but from him that hath not shall be taken away even that which he hath.” The nature of knowledge and vocabulary acquisition all but assures that children raised in language-rich homes gain in reading comprehension, while the language-poor fall further behind (see “A Wealth of Words,” Winter 2013). “The mainspring of [reading] comprehension is prior knowledge—the stuff readers already know that enables them to create understanding as they read,” explains Daniel Willingham, a cognitive scientist at the University of Virginia.

To make matters worse, most reading curricula have focused on developing generalized, all-purpose reading-comprehension “skills” uncoupled from subject-specific knowledge—reducing a complex cognitive process to a collection of all-purpose “reading strategies” to be applied to any book or bit of text that a student might encounter. Attempts to teach reading comprehension as knowledge-neutral put an enormous premium on student engagement. For teachers, reading instruction can often feel more like cheerleading: sell kids on the magic of books, get them to read a lot, and—voilà!—they will emerge as verbally adroit adults with a lifelong love of reading. As generations of results show, this approach doesn’t work.

The “reader’s workshop” model, in which countless New York City elementary school teachers have been trained, is typical of this focus on “skills.” A workshop “mini-lesson” might begin with a teacher “modeling” a skill or reading habit as her wide-eyed charges gather around her. A lesson might be “good readers stay involved in a story by predicting” or “good readers make a picture in their mind while they read.” Teachers “model” these supposed good reading habits by reading to students, stopping frequently to do a “think aloud,” demonstrating how they are applying these strategies to make sense of a story. Then the children are sent off to practice the skill independently or in small groups, choosing from various “high-interest” books at their individual, “just-right” reading level. While the children read, teachers circulate, ensuring that their students understand the new skill. (It remains to be seen how, or if, the reader’s workshop model can be squared with the Common Core. The two approaches appear to be irreconcilable, but educators like Lucy Calkins claim otherwise.)

To the uninitiated, reader’s workshop can seem strange, even cultish. Visit any elementary school and you’re nearly certain to see posters reminding children how and what to think while reading: “Good readers visualize the story in their minds.” “Good readers ask questions.” “Good readers predict what will happen next.” Books quickly fill up with sticky notes as students learn to stop every few pages to jot down their questions and “noticings.” Teachers coach children to be vigilant about aspects of a story that remind them of their own lives and presumably enable them to understand better what they read. Discussions, even among the youngest children, sound rich and fruitful, with children making “text-to-self” or “text-to-text” connections, and classmates politely agreeing, disagreeing, or “adding on,” in the argot of “accountable talk.”

The ideas fostered in the workshop model (for example, that teachers should use interesting reading materials and encourage a positive attitude toward reading) are thoughtful and humane but insufficient to ensure reading success. Low-income children from knowledge- and language-poor homes need much more. To appreciate why, one must understand something about the nature of reading itself.

Most people think of reading as similar to riding a bike—something we learn to do as children and never forget. Moreover, you likely perceive both riding a bike and reading as transferable skills. Once we learn how to pedal and balance, we can apply those skills to every bike, and so it appears with reading. Once you know how, you can read a novel or a newspaper editorial with equal ease and fluency. Some may read faster, slower, or more or less carefully than others, but generally speaking, either you can do it or you can’t.

This view of reading is only partially accurate, however. Translating written symbols into sounds, or “decoding,” is indeed a transferable skill. This explains why it’s easy to agree on the pronunciation of made-up words such as “churbit” or “trodle.” Add an extra “d”—troddle—and we agree that the pronunciation changes from trow-duhl to trah-duhl. This is the magic of phonics, which remains the essential starting point in teaching children to read from the first days of school. The “reading wars” of recent memory, which pitted phonics against whole language, are largely settled. Phonics won, but the low reading scores that give educators such fits typically have less to do with decoding problems than with children’s inability to understand adequately what they are reading.

Reading comprehension, like critical thinking and problem solving, is what psychologists call “domain-specific”: you need to know something about a topic to be able to think about it. Faced with a text passage about the customs of New Amsterdam, the student familiar with the topic may breeze through with relative ease. For the student who has no idea who the Dutch were, or is unfamiliar with early New York history or has never heard the word “custom,” the passage is a verbal minefield. To shift metaphors, a piece of text is like a tower of wooden blocks, with each block a vocabulary word or a piece of background knowledge. Pull out two or three blocks, and the tower can still stand. Pull out too many, and it collapses.

Imagine taking a child to his first baseball game. If you know baseball, you will easily explain what’s happening. You draw the child’s attention to the most important actions on the field, reflexively tailoring your explanation to the child’s level of understanding. If the child knows nothing about baseball, you might explain the basics: what the pitchers and batters are doing. Balls and strikes. Scoring a run when a player makes it all the way around the bases without being called out. You’d explain what an “out” is. If the child knows the game or plays Little League, you might instead draw his attention to game strategy. Would a bunt or a stolen-base attempt be the best move at a crucial moment? You might point out when the infielders move in, hoping for a double play.

Now imagine attending a cricket match and doing the same thing, assuming that you know nothing about the game. Your knowledge of baseball doesn’t transfer to cricket, though both games feature balls, bats, and runs. “Sports comprehension strategies,” if such existed, would be of no use. Your ability to make sense of what’s happening in front of you and to explain it to a child depends on your knowledge of the specific game—not your ability to connect what you notice to other games that you understand. The same is true of reading. Even if you aced the verbal portion of your SATs, you will find yourself in situations where you are not an excellent reader. You might struggle to make sense of a contract, say, or a new product warranty. Your tech-savvy teenage daughter might have an easier time understanding the instructions for upgrading a computer operating system. You didn’t suddenly become a poor reader in these situations; you’re merely reading out of your depth.

Reading comprehension, then, is not a skill that you teach but a condition that you create. Teachers foster that condition by exposing children to the broadest possible knowledge of the world outside their personal experience. As Daniel Willingham aptly titled one of his instructional YouTube videos a few years ago, “Teaching content is teaching reading.”

The specific body of knowledge that students need for broad reading competence is open to debate, but a useful guideline is to emphasize the common body of knowledge—from basic knowledge of history and science to works of art and literature—that most literate Americans know, as reflected in their speech and writing. This has been the precise aim of E. D. Hirsch’s Core Knowledge movement. Hirsch’s critics have often accused him of attempting to impose a rigid canon, but Core Knowledge is better understood as an attempt to curate and impart the basic knowledge of history, science, and the arts that undergirds literate speech and writing. Regardless of whether schools adopt the Core Knowledge approach or develop their own catalog of essential knowledge, knowledge acquisition belongs at the heart of literacy instruction.

Reading more helps, yes, but not because we are “practicing” reading or improving our comprehension skills; rather, reading more is simply the most reliable means to acquire new knowledge and vocabulary. Prior knowledge is indispensable. Even in the reader’s workshop model, teachers often encourage children to “activate your prior knowledge” to enhance understanding. But building prior knowledge has rarely been viewed as the reading teacher’s explicit role—at least not until the advent of the Common Core State Standards, which New York has embraced enthusiastically.

First unveiled in 2009, the Common Core State Standards are not a curriculum. They don’t designate the specific works of literature or body of knowledge that students must know. But the standards are emphatic about the link between a knowledge-rich curriculum and reading comprehension: “By reading texts in history/social studies, science, and other disciplines, students build a foundation of knowledge in these fields that will also give them the background to be better readers in all content areas. Students can only gain this foundation when the curriculum is intentionally and coherently structured to develop rich content knowledge within and across grades.” Herein lies a crucial insight that must precede any serious effort to improve reading achievement: broad general knowledge correlates with broad general reading ability. A “foundation of knowledge” is a necessary precondition if students are to become stronger readers.

Common Core’s critics mistakenly characterize the standards as micromanaging classrooms. The standards don’t dictate what children must read any more than auto-safety standards determine what car one drives. Instead, they form a framework for instruction. “There is no such thing as doing the nuts and bolts of reading in kindergarten through fifth grade without coherently developing knowledge in science, and history, and the arts, period,” explained David Coleman, Common Core’s chief architect, in a 2012 speech in Washington, D.C. “It is the deep foundation in rich knowledge and vocabulary depth that allows you to access more complex text,” he said.

New York’s successful 2010 Race to the Top application focused on improving curriculum, the long-overlooked lever in the education-reform playbook. As part of the state’s transition to Common Core, the New York State Education Department (NYSED) funded the development of curriculum materials for statewide use in English language arts and math. The Virginia-based nonprofit Core Knowledge Foundation (where I served as vice president until December 2012) won a contract to produce a statewide version of the New York City reading curriculum that it piloted in 2008 under Chancellor Joel Klein (see “A Solution for Gotham’s Reading Woes,” Summer 2011). In city schools that retained the Core Knowledge curriculum after the pilot program ended in 2011, foundation officials describe students’ progress as “encouraging.” The comparative success of these schools offers a tantalizing glimpse of the reading gains possible when schools adopt a well-rounded, knowledge-rich curriculum, implement it effectively, and stick with it.

In February 2013, NYSED recommended that city schools use the state’s Core Knowledge curriculum along with Pearson’s ReadyGEN. These programs include an intensive dose of phonics married to a series of lessons that stay on a single topic for weeks at a time—exactly the kind of approach to literacy prescribed under Common Core. Proof of the city’s seriousness about a phonics- and knowledge-rich approach to reading is also evident in the curriculum that it did not choose: the Teachers College Reading and Writing Project, which has dominated city classrooms for more than a decade. City education officials take care to say that schools may continue to use Teachers College programs. But school administrators surely noted the shift.

Education is “not the filling of a pail but the lighting of a fire,” goes a popular teacher adage. Empty buckets seldom burst into flames. A stubborn refusal to be prescriptive about what children read, to put the accumulation of knowledge at the heart of the elementary and middle-school reading curriculum, has almost certainly hindered the reading ability of millions of children. Vast amounts of class time that might have been spent engaging kids with the world beyond their experience have been squandered. Instead, there is endless teaching, reteaching, and practicing the spurious skill of comprehension, hoping that children will somehow “catch” a love of reading.

Raising reading achievement means playing the long game. There are no quick fixes. It is a very different challenge from teaching math, where standards, curriculum, and assessments tend to be closely aligned. In reading, even the best standards leave the choice of specific texts to the discretion of individual teachers and schools. Thus reformers fight pitched battles over English class reading lists. More classics or more contemporary books? Is it better for a middle-schooler to read Twilight or The Scarlet Letter? What these debates tend to overlook is the importance of background knowledge. Complaining that high school students no longer read, say, Huckleberry Finn is an empty criticism if a student comes to the book knowing nothing of nineteenth-century America, riverboats, or slavery, or cannot find the Mississippi River on a map. Absent this background knowledge, Mark Twain’s novel will be merely another book that students read but do not understand. Past generations of schoolchildren who enjoyed (or didn’t enjoy) Huckleberry Finn had this knowledge base as they read the book. Today, too many students from low-income households do not.

The Common Core Standards make clear that building knowledge is imperative, but this is all that they can do. Coleman has said that the Common Core “restores elementary teachers to their rightful place as guides to the world.” It’s an image that perfectly captures how to build strong readers—by focusing their attention on the world outside their windows, rather than limiting them to the world inside their hats, or worse, underestimating them by assuming that they could not possibly be interested or engaged if curricular content is not directly relevant to their daily lives. Even the most dedicated teachers cannot cram a lifetime’s worth of knowledge and vocabulary into 180 days of reading instruction. But if our schools are not intentionally and coherently building knowledge, they’re not teaching reading.