How Background Knowledge Builds Good Readers and Why Knowledge Building ELA Curricula Are Vital
A common base of content knowledge and coherent, comprehensive, and sequential curricula to deliver it are prerequisites for reading comprehension. Most students are not getting what they need.
“[R]eading comprehension depends heavily on knowledge. By failing to provide a solid grounding in basic subjects, we inadvertently hobble children’s ability in reading comprehension. As I put it elsewhere, teaching content is teaching reading.” —Dan Willingham
The surge of support for the science of reading is cause for great cheer. According to the Albert Shanker Institute, 45 states and the District of Columbia have passed laws since 2019 to shift reading instruction based on what research says works. These laws often explicitly call for teaching phonics, phonemic awareness, and other skills that enable decoding of words. Implemented well, these laws will produce many more third graders who are strong decoders. But reading comprehension also requires students to have background knowledge—a rich store of content knowledge in history, geography, social studies, science, and the arts related to the topics students are reading about. And while a few of these states’ laws (and only a few) mention background knowledge, no state gives it more than a passing reference.
The future adults sitting in classrooms today will not fully comprehend future newspapers (or whatever replaces them) unless they are grounded in this relevant content knowledge. They also will not understand middle school science textbooks if they have not already soaked up at least the basics of adaptation, gravity, and sound waves. They will not understand their high school and college history texts without a store of knowledge on such topics as the Civil War, civil rights, and geography.
The future adults sitting in classrooms today will not fully comprehend future newspapers unless they are grounded in this relevant content knowledge.
Readers need this background knowledge to make sense of what they read. Take for example, this sentence from a recent Washington Post article on the war in Ukraine:
He drew a comparison to World War I, explaining how strategists a century earlier had predicted a swift end to the bloodshed, only for it to become an unwinnable standoff that killed millions and set the stage for World War II.
As is often said, history rhymes. Echoes from the past often reverberate in current public policy debates. Without knowing history, a reader cannot make much sense of this sentence. She may have excellent decoding skills and even be pretty good at finding the main idea, summarizing, and considering evidence for claims. But only the reader who is familiar with the World Wars will gain insight—drawing a parallel to the current situation while perhaps also learning that some predicted World War I would be short.
Students need a remarkable breadth of word and world knowledge if they are to succeed in high school, go on to college, and read newspapers and popular books. Most will only acquire that knowledge if their schools have an intentional, effective plan to impart it, allowing them to learn it incrementally and efficiently starting in the earliest grades.
Students need a remarkable breadth of word and world knowledge if they are to succeed in high school, go on to college, and read newspapers and popular books.
But American schools do not do a good job of building content knowledge. They barely teach either social studies or science in elementary school—on average just 16 minutes a day for social studies and 18 for science in K-3, according to a 2018 survey. In upper elementary, the time for social studies grows by just 5 minutes; in science, it grows to 27 minutes. The lion’s share of time goes instead to the English language arts (ELA) block, which has grown in recent years—ironically, to strengthen reading achievement.
Yet the most important tool to build reading comprehension is a curriculum that charts a path—starting in the earliest grades—by which schools can intentionally build the content knowledge that constitutes background knowledge. That knowledge-building curriculum is essentially absent from American schooling.
Compounding Power of Content Knowledge
The now iconic “baseball study,” published in 1988, underscores just how much background knowledge matters to comprehension. Based on a reading comprehension test, researchers Donna Recht and Lauren Leslie identified students as strong or weak readers and as having either high or low baseball knowledge. The students were given a text that described half an inning of baseball. Recht and Leslie then gave students a replica of a baseball field and asked them to depict what had happened during the half inning and scored them both quantitatively and qualitatively. Notably, the students with weak reading skills but strong baseball knowledge scored higher (27.5 and 19.4) than the strong readers with low baseball knowledge (18.8 and 12.7). Topic knowledge trumped generic reading skill!
Knowledge compounds. Consider this sentence from the book Bats, by Gail Gibbons: “In places where it gets cold in the winter, some kinds of bats migrate to warmer climates; others use their roosts to hibernate until spring.” As the Knowledge Matters Campaign explains, readers who already have basic knowledge of what it means to migrate and hibernate can make sense of this sentence while they also gain new understanding about the tremendous variation in bat species. They would learn a bit more about bats, habitats, hibernation, climate, and the connections among them.
Gains in vocabulary also compound. Tom Landauer indicates that when students read about a topic with which they are already familiar, they learn four times more new vocabulary than students without that topic familiarity.
In short, for the student with relatively more knowledge, every read—and especially every read with a familiar topic—begins a virtuous circle: Having more vocabulary and knowledge at the outset produces greater growth in vocabulary and topic knowledge. This virtuous circle enables students to read ever more advanced texts, which, in turn, produces yet greater learning. After a few well-sequenced texts, the student reading Bats not only knows more about bats but also about adjacent topics.
Having more vocabulary and knowledge at the outset produces greater growth in vocabulary and topic knowledge.
But for the student without adequate knowledge to begin with, the circle is downward and vicious. As E. D. Hirsch, a long-time explainer of the importance of background knowledge, wrote,
The less advantaged child, by contrast, suffers a double (or triple) loss. The exposition is puzzling from the start, because the child doesn’t know enough of the words. He therefore fails to gain knowledge from the exposition and also fails to learn new word meanings from the context. And to intensify that double loss, the child loses even that which he hath—his interest, self-confidence, and motivation to learn.
This fundamental reality about reading was dubbed the Matthew Effect in the 1980s, after the passage in Christian scripture that says he who “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 knowledge gap that launches this downward spiral starts as a language gap before students even enter school. In a path-breaking book, Betty Hart and Todd Risley established that by age 4, the average child in a professional family would have heard almost 45 million words; an average child in a working-class family, 26 million; and an average child in a low-income family, just 13 million. These differences snowball and help explain the large gaps in reading scores among high- and low-income students.
The Role for Curriculum
To become more intentional and efficient about building students’ broad, deep background knowledge, state leaders have to reckon with curriculum—long in the purview of local leaders and educators. Knowledge builds on knowledge, so lessons and units must be sequenced so they build on each other.
They also must build on the wider universe of cognitive science that explains how students learn. Learning flows from what they think about. So new learning is strengthened when students recall and think about it at key intervals. And before children can decode, they can build knowledge from regularly sequenced read-alouds.
Dan Willingham recalls a lesson that a teacher described to him, intended to teach about the Underground Railroad. In the lesson, students baked biscuits
because this was a staple for the enslaved people seeking escape. He asked what I thought about the assignment. I pointed out that his students probably thought for 40 seconds about the relationship of biscuits to the Underground Railroad and for 40 minutes about measuring flour, mixing shortening and so on. Whatever students think about is what they will remember.
Willingham has written that “memory is the residue of thought.” What you learn and remember “is not a product of what you want to remember or what you try to remember; it’s a product of what you think about.” These tidbits from cognitive science hint at how much more productive, focused, and long-lasting learning can be if the lessons, activities, and units students experience are constructed and sequenced across a year and across grades to optimize learning.
Constructing that sequence and all the lessons and units within it is beyond the scope and reach of any one teacher. No matter how expertly or frequently a teacher scours Pinterest or the many available curriculum and lesson-sharing and curriculum sites, it is not realistic to expect them to conceive, sequence, and prepare a daily stream of lessons that take optimal advantage of learning science. And unless all teachers are working off the same curriculum, they are not positioned to build on what students learned in prior years or prepare students with the prior knowledge needed for subsequent years.
The beauty of a curriculum is that it can provide all this. Whatever the subject matter, good curriculum is systematically and coherently sequenced and comprehensive, including the texts students will read, the learning activities, and whatever else is needed. Otherwise, its value would quickly diminish.
Whatever the subject matter, good curriculum is systematically and coherently sequenced and comprehensive.
In a different world, early elementary students would already spend a good deal of time learning history/social studies, science, and the arts. In this imaginary world—imaginary in the U.S., but the norm elsewhere—there would be a strong curriculum in each content area, starting from the earliest grade. Taught based on these curricula, many more students would be well prepared to enter middle and high school with a relatively common store of knowledge, equipped to wrestle with more advanced content from a roughly common, equitable threshold. The curriculum would anchor professional development. Assessments would be tied to the curriculum, letting students and teachers know whether learning is on track. The importance of teaching this general knowledge would be well understood and strongly embraced.
But alas, that is not our world. These basic building blocks—detailed, well-sequenced elementary standards in each of these subjects and aligned curricula, professional development, and assessments—do not generally exist. Even the time for instruction in the subject areas barely exists. Given this world, how does the savvy state board proceed?
Promising Developments to Build On
It is no fluke that American schools lack the basic building blocks for such curricula. Given this country’s strong tradition of local control when it comes to curriculum, state education agencies have typically steered clear of mandating curriculum. They give districts wide latitude and flexibility. Most districts, in turn, push that flexibility to the school level, opting not to require adherence to a strong district curricula.
The trade-offs are real: flexibility yes, but also less opportunity for the optimal learning a curriculum provides, less (or no) opportunity for curriculum-based professional development and collaboration (discussed in David Steiner’s article in this issue), for building knowledge intentionally across grades, and for providing teachers with thoughtful, sequenced lessons, reducing their need to scour the internet late at night. And as it turns out, the flexibility to neglect key subjects.
Yet two hopeful things are happening. First, a handful of states are exploring and finding ways to navigate the trade-offs between local control and the need for coherent curriculum. Second, a few publishers of ELA curriculum are making background knowledge central to their materials.
State Incentives for High-Quality Curriculum. Understanding that good curriculum is vital to strengthening achievement, a number of states have been working to encourage their districts to adopt high-quality curricula in ELA and math. Given traditions of local control, the emerging strategy relies on incentives, beginning with simply helping districts identify high-quality curricula.
Louisiana has led the way over the past decade. The state education agency (SEA) first identified high-quality ELA curricula and then provided a variety of incentives for districts to adopt these curricula.
Critically, the state involved educators in developing the rubrics for rating how well commercially available curricula reflected the Common Core standards, an effort undertaken with outside groups that had experience in developing such rubrics, including Student Achievement Partners and Achieve. Teams used the new rubric to review and rate curricula as Tier 1, 2, or 3. Meanwhile, the state teed up incentives and user-friendly tools tied to use of the Tier 1 curricula. These included purchase discounts and a streamlined procurement process. As others in this issue detail, other states are putting similar incentives in place, several as part of the Council of Chief State School Officers’ High Quality Instructional Materials and Professional Development network.
At first, few ELA curricula met Louisiana’s Tier 1, so the SEA created the Louisiana ELA Guidebooks, which included tightly aligned formative assessments and professional development. That in turn allowed Louisiana to create a pilot assessment under the Every Student Succeeds Act (ESSA) that aligned to the guidebooks. This was an important departure. Students understand texts better and score better on tests when they are familiar with the topics and vocabulary in them, but ESSA tests by design are based on random knowledge, providing no external incentive to learn a particular set of topics well.
Louisiana instead proposed that the state assessment reflect what was taught. In this way, according to the state’s application for the pilot grant, Louisiana intends to ensure that “all students have an equal opportunity to succeed on the test.” Notably, educators who use the aligned curricula and assessment will now have a window on how well their students understood what was actually taught—and be able to consider appropriate adjustments.
ELA Curricula That Build Knowledge. Core Knowledge Language Arts (CKLA), for example, explicitly recognizes and takes to heart its role as the main source of students’ content knowledge. (Disclosure: I was a long-time member of the Core Knowledge Foundation’s Board of Trustees.) As should be the case with a solid ELA curriculum, CKLA is very strong in decoding, writing, and literature. At the same time, it builds content knowledge in geography, history/social studies, science, and the arts, introducing and building on topics in intentional, systematic, thoughtfully sequenced ways. Its second grade curriculum introduces such topics as Early Asian and Ancient Greek civilizations, “Cycles in Nature,” the U.S. Civil War, and insects, with units in subsequent grades building on these units. The topical units support ELA standards as well, including, for example, writing assignments that require thinking about key content while providing students opportunities to learn and practice new writing skills.
While not explicitly taking responsibility for building students’ overall subject matter knowledge in the same intentional way, a few other curricula nonetheless take it seriously. For example, most of Wit and Wisdom’s modules impart important background-building knowledge. The material within each is extremely well sequenced, including readings, discussions, and writing activities on topics within the theme. Second-grade modules are themed “A Season of Change,” “The American West, “Civil Rights Heroes” and “Good Eating, with each including literary selections, other readings, and activities that build knowledge and understanding of science, history, and literature understanding.
How State Boards Can Help
U.S. reading scores will rise and students will be better readers when they are learning from elementary curricula designed to build their background knowledge effectively. How can state boards move this work forward?
Explain and educate. The first step, as with virtually any new line of board work, is to educate yourselves, state and district agency leaders, educators, and residents about the importance of background knowledge. One terrific starting point: Survey elementary teachers to find out how much time is currently spent on history/geography/social studies, science, and the arts. Perhaps follow up by inviting experts to speak to the board, state agency staff, and key stakeholder leaders. Consider that at some point you will want to identify key leaders across these groups to further engage and educate their peers.
Work to enact key policies. In the longer run, the goal is to work with your state agency to enact policies that 1) identify high-quality ELA curricula that intentionally build background knowledge, especially in the elementary grades and 2) encourage and incentivize local districts to adopt these curricula. Such incentives could include discounts made possible through state contracts, high-quality professional development and/or benchmark assessments aligned to and offered as part of the purchase agreement, and even final assessments that are aligned.
Seek more information. The Knowledge Matters Campaign, whose central priority is exactly this issue, has released a tool to help judge how well an ELA curriculum builds needed background knowledge. State leaders can also learn from peers in the IMPD network, likely have the greatest expertise in ways to help districts adopt and implement the best curricula. States already incentivizing the adoption of high-quality curricula can stretch to focus on background knowledge and help districts and educators understand the importance of doing so.
The work will not be easy or fast, and there are issues to work through—for example, what topics to prioritize and how to integrate with existing state standards in these subjects. The good news is that good curricula for building students’ background knowledge exist. A strong model for incentivizing districts to adopt and implement good curricula also exists. Research backs these efforts. Unlike a decade ago, state education leaders have a solid foundation to build on.
Ruth Wattenberg was president of the District of Columbia State Board of Education in 2019–20 and a member from 2015 to 2022. Previously, she was director of educational issues for the American Federation of Teachers and editor of its professional issues magazine, the American Educator.
 Susan B. Neuman, Esther Quintero, and Kayla Reist, “Reading Reform across America: A Survey of State Legislation” (Albert Shanker Institute, 2023).
 Donna R. Recht and Lauren Leslie, “Effect of Prior Knowledge on Good and Poor Readers’ Memory of Text,” Journal of Educational Psychology 80, no. 1 (1988).
 T.K. Landauer and S.T. Dumais, “A Solution to Plato’s Problem: The Latent Semantic Analysis Theory of Acquisition, Induction, and Representation of Knowledge,” Psychological Review 104, no. 2 (1997) : 211–40, https://doi.org/10.1037/0033-295X.104.2.211. Cited in E.D. Hirsch, “Building Knowledge,” American Educator (Spring 2006).
 Keith E. Stanovich, “Matthew Effects in Reading: Some Consequences of Individual Differences in the Acquisition of Literacy,” Reading Research Quarterly 21, 4 (Fall 1986): 360–407. Cited in E.D. Hirsch, “The Case for Bringing Content into the Language Arts Block and for a Knowledge-Rich Curriculum Core for All Children,” American Educator (Spring 2006).
 Natalie Wexler’s excellent The Knowledge Gap includes research evidence and on-the-ground reporting about this issue.
 Betty Hart and Todd Risley, Meaningful Differences in the Everyday Experience of Young American Children (Paul H. Brookes Publishing, 1995).
 Daniel T. Willingham, “Ask the Cognitive Scientist: Why Do Students Remember Everything That’s on Television and Forget Everything I Say?” American Educator (Summer 2021).
 Julia Kaufman, Lindsey E. Thompson, and V. Darleen Opfer, “Creating a Coherent System to Support Instruction Aligned with State Standards: Promising Practices of the Louisiana Department of Education,” report (RAND Corporation, 2016).
Also In this Issue
A network of states move the needle on quality without usurping local control.
State boards can take a lesson from the work of leading states.
Overcoming barriers to faithful implementation requires changing teacher and leader mind-sets.
A common base of content knowledge and coherent, comprehensive, and sequential curricula to deliver it are prerequisites for reading comprehension. Most students are not getting what they need.