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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.)


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.

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).

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 get your head around the issue? 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 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!

  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

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