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Essential Research No One Knows: Knowledge Matters To Reading Comprehension

Friends, let’s talk about poorly-understood research that has the potential to turbocharge your reading outcomes:

Students’ background knowledge matters more to their reading comprehension than their reading skill. REALLY.

Research has proven this, most famously in The Baseball Study by Recht & Leslie.

This video explains the study so well in 3 minutes that I am just gonna insist that you watch it right now, ’cause I can’t write it any better. (I’ll wait.)


Alternately, this outstanding Learning to Read Primer (Part 2) explains the Baseball Study on pages 4 through 8. In addition, Part 1 frames the research beautifully (especially pg. 10-14).

Eye-opening stuff, right?!?

Cognitive science guru Daniel Willingham summarizes the same research in a video (skip to 5:25). He notes that this study has been repeatedly replicated with other subjects – from photocopy technology to the Vietnam War – with the same outcome. (In fact, he noted in a tweet thread that researchers have stopped trying to replicate this study because “the effect is known;” instead, they account for this significant effect in statistical analysis.)

The upshot: background knowledge is key to reading comprehension.

Equity enthusiasts, take note: when this research sinks in, you realize that privileged students start on third base from a literacy perspective. (See what I did there?) They arrive at school with the benefit of more travel, museum visits, and parents talking about geeky academic stuff, so they just know more about the academic world. We need to be especially focused on building content knowledge for our less privileged students. Kids from less affluent families show up with lots of knowledge about their worlds, but not about the subjects that show up on assessments (think science, social studies, the arts).

Another key equity insight: content knowledge is an even greater predictor of comprehension for English language learners. This research truly holds the keys to equitable reading outcomes.

The takeaway for all students: background knowledge about a subject fosters reading comprehension.

So, what are we doing about this information in schools? We’re spending loads of time on science and social studies in order to teach kids about the world, giving them a rich bank of content knowledge to propel their reading success… right?

Wrong. We’ve actually been spending less time on those subjects. The Knowledge Matters campaign notes “a period of de-emphasizing science and social studies at the elementary grades” over the last 20 years, in which “time spent in 1st-4th grade social studies and science classes has decreased – down by nearly an hour and a half a week.”


this is every reader right now


So, that’s problem #1. We’re ignoring the research on content knowledge-as-reading-catalyst with the diminished time for science and social studies.

Where’s the extra classroom time going? It’s going to reading instruction: “time dedicated to reading instruction has increased – to more than two-and-a-half hours a day.”

That sounds smart… until you look at our outcomes. We’ve added time for reading instruction across our schools, yet we have essentially flat reading outcomes in the same period (in addition to the gutting fact that only a third of our students are proficient readers, as Emily Hanford reminds us):

US NAEP reading proficiency scores, initially published in Hard Words by Emily Hanford
our national reading outcomes. everyone in K–12 should look at this daily.


Why isn’t the extra time for reading – which is surely intended to improve reading outcomes – paying off? Here’s what researchers find: the additional time tends to be used on reading strategies and skills instruction. There’s a place for that instruction, but it has unfortunate diminishing returns, and we’re overdoing it. Which is problem #2.

The Knowledge Matters folks say it best: ‘Instead of using the extra time to read, discuss, and understand texts that intentionally build students’ vocabulary and knowledge of key topics in science and social studies, an excessive focus has been put on practicing reading comprehension skills such as “finding the main idea,” “making inferences,” and “understanding text features.”’

Literacy experts believe that problems #1 and #2 conspire to explain our poor national reading outcomes.

So, let that sink in… in our quest to improve reading outcomes, we’ve been decreasing time on the very subjects that build content knowledge for kids, which hamstrings our reading outcomes… and we’ve given more time to reading instruction, using approaches that don’t move the needle on reading outcomes.



School Yourself

More folks need to know this essential info! And you, friend, may want to know more.

Here are my fave resources for explaining and understanding this research, besides the ones above. (Which are fabulous and all. I could Tweet that 3-minute video on The Baseball Study all day long… I’ve seen it drop more jaws than anything else I have ever shared, on any topic.)

Want a layman-friendly intro to the research? How to Get Your Mind to Read by Daniel Willingham is an excellent primer, and an easy share with parents. Read it, Tweet it, hand it out at your next PLN meetup.

Want to understand this research within the broader context of how kids learn to read? These Learning to Read Primers (Part 1 and Part 2) are outstanding. Must-read. Share with everyone you know.

Want to go deeper on the background knowledge research? In 10 minutes, Daniel Willingham makes it all super-tangible in this info-rich video:


Want instructional guidance on building content knowledge? The Knowledge Matters campaign’s superb informational overview is your must-read. Come for the research, stay for the examples of what good looks like at a classroom-level.

Want to understand why spending loads of time on reading skills and strategies isn’t a successful approach? Read Can Reading Comprehension be taught? by Daniel Willingham.

Want to go deep on this topic? Natalie Wexler wrote the book on it, and the whole world seems to be reading The Knowledge Gap right now.

Want to persuade someone that this research truly matters? Sue Pimentel, literacy goddess and lead author of the CCSS in ELA, names it as one of her three Must-Wins to improve reading outcomes in Education Week.

Want to laugh at ’80s hairstyles while you watch educators experience this principle in action? This video is one part genius explanation (really… it’s legit informative), one part comic relief, one part proof that we have known this research for a looooooong time:


School Your Friends

I’d say that this is the most ‘Aha!’ moment-generating info in all of K–12 education.

It’s not completely unknown to educators. I meet plenty of savvy literacy leaders who know it. My Mom knew it before I knew it. Still, my travels in K–12 suggest that maaaaaybe 10% of educators know this info. We gotta change that.

So please, friends, post it, Tweet it, email it, preach it. Skywrite it if you can. Knowledge matters to reading comprehension, and we can propel kids’ reading outcomes if we align our instruction around that truth.


Applying This Research In Classrooms

A postscript, added after my wise Mom pointed out some gaps in the piece.

Solutions I Dig:

I would want educators to read this and think, “My school should consider how we’re building content knowledge for our students, at the same time as we’re supporting their foundational skill development in reading. That’s the game-changing Both-And.”

My favorite solution in this regard is purpose-built curriculum. Sue Pimentel put it best:

“Given that time is a scarce commodity in most schools, the takeaway for school leaders is to incorporate rich content, organized around conceptually-related topics, into the reading curriculum so that students learn new information about the world while they develop as readers.”

Exemplars help, so here’s one: the EL Education K–5 Language Arts curriculum builds each unit around a text set on a science or social studies topic:

EL Education K-5 Module Topics

I hope to write more about some other knowledge-building curricula in the months to come. In the meantime, you can read about these curricula in classrooms via the Knowledge Matters school tour.

Not Good:

I would not want anyone to think that I recommend scaffolding the heck out of every text, spoon-feeding the info contained within to students before they read, in a well-intentioned but misguided attempt to build background knowledge for kids. Students should be acquiring their knowledge about the world from the texts (or better yet, text sets), not from overteaching.

Good talk, y’all.


Extra Credit

Hey socialites, if you’re gonna share in social, here’s my fave quote from the insightful Knowledge Matters piece. Share on!

Thanks for spreading the word about this essential research. Kids win when we bring this conversation to new education PLCs.

literacy reading content knowledge

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  1. Karla Karla

    Has The Baseball study been replicated? It is 30 years old. It would be interesting to know if results would be the same.

    • karenvaites karenvaites

      Yes, it has been replicated many times. See this video from cognitive science guru Daniel Willingham (skip to 5:25). He notes that this study has been repeatedly replicated with other subjects – from photocopy technology to the Vietnam War – with the same outcome:

  2. Though I don’t disagree about the importance of teaching content, I think we must be careful not to assume that content is the secret to improved reading. Of course, we know that context helps, and a content background provides context, but a good English teacher will teach kids strategies to increase their reading skills.

    In the younger grades, the acquisition of sight word vocabulary and phonics skills are critical to good reading.

    I’m suspicious of any report on research that uses the word “proves.”

    • karenvaites karenvaites

      Indeed, there are no magic bullets in the process of learning to read. Thank you for taking the time to read the blog!

    • I fear you don’t really know what you’re on about – comprehension strategies complement, not interfere with, delving into background knowledge. But such strategies are general in nature and don’t help when background knowledge is low.

      • Kate Rosen Kate Rosen

        She does know what she’s on about. “Comprehension strategies” steal educational time from teaching skills that are fundaments: without accurate and automatic decoding — which should be explicitly and systematically taught — and rich content knowledge, teaching “comprehension strategies” replaces teaching the things that actually DO foster comprehension. Don’t take my word for it. Check the science that’s emerged in the last 10 years.

  3. Can anyone weigh in on how this applies to adult ESL? We also reflexively apply a single reading level to students, as well as harping on skills like reading for main idea and inference, skills now shown not to apply across texts

  4. […] way that they get all kids working with grade level texts; a content knowledge-building approach (which is key, based on research); strong writing components; use of formative assessments; and […]

  5. Can you help us understand this statement?: “Why isn’t the extra time for reading – which is surely intended to improve reading outcomes – paying off? Here’s what researchers find: the additional time tends to be used on reading strategies and skills instruction.”

    Here’s the problem that parents/educators face when blanketed by urgent redirection to focus what appears to be only knowledge w/o acknowledging the simple view of reading. For what it’s worth, students with dyslexia often arrive in PK and K with a HUGE knowledge base, but still don’t learn to read.

    Your blog post, begs the question: Does the quote above mean that schools are teaching “too much PA and phonics strategies” and/or “comprehension strategies” and not enough background knowledge to support reading? Parent and educator experience across the US show that schools only lightly touch on decoding instruction and phonemic awareness is an alien concept. Many educators argue that these PA/phonics “skills and strategies” are “ill-conceived and rigid reading programs.”

    For the uninitiated, the blog post appears to say that “skills” training”, which could mean PA/phonics to some, is not worthwhile. Parents and educators find high school students without any decoding abilities and reading comprehension is years below grade level. These same students have spoken language comprehension above grade level. When we leave out info on decoding, we open up ourselves to pouring a knowledge base where decoding is needed.

    This is a long-winded way to offer a caution: please briefly include what is meant by skills and strategies — does it mean PA/phonics? Does it mean grammar and spelling? Does it mean learning discrete skills w/o including any background knowledge? Acknowledging the SVR equation can help frame the components of effective reading instruction for parents and educators so they can be part of the conversation with their districts on how to invest time and money for reading instruction.

    In our haste to move back to basic knowledge, let’s not throw the baby out with the bathwater. Why not acknowledge that even if a student is proficient in language comprehension they might struggle to read and instruction in PA/phonics is necessary for skilled decoding and ultimately for understanding what they read. Thank you!

    • karenvaites karenvaites

      Thank you for asking! All students do need to developing the ability to decode words; additional color can be found in this phonics blog:

      I appreciate your caution about the need to be clear about which forms of skills and strategies instruction are problematic. Thanks for reading!

  6. You know what kills me? When teachers, parents, and even STUDENTS think that building background knowledge before reading content is somehow “cheating.” We’ve developed this weird mindset -probably as a result of standards testing – that reading comprehension is a skill assessed solely by “cold reads” disconnected from anything kids are actually learning.

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