Core Knowledge got its start from E.D. Hirsch’s years teaching literary theory as an English professor, he writes in How Two Poems Helped Launch a School Reform Movement in The Atlantic. He discovered the importance of background knowledge when he looked at ways to improve college students’ writing.
When the topic was familiar to readers, you could measure the benefits of good writing (and the problems caused by bad writing) quite consistently. But the time and effort it takes to understand a text on an unfamiliar topic completely overwhelms the effects of writing quality.
At a Richmond community college, students couldn’t read or write clearly because they lacked a base of knowledge, Hirsch writes.
These students, primarily from disadvantaged backgrounds, could easily read a text on “Why I like my roommate.” But even after controlling for vocabulary level and syntax, they could not easily read about Lee’s surrender to Grant. These Richmond students, surrounded by Civil War mementos on Monument Avenue, were clueless about the Civil War. Their lack of knowledge was the reason they were unable to read well about anything beyond the most banal topics.
Researchers have found that “relevant prior knowledge — information already stored in one’s long-term memory — is the single most important factor in reading comprehension,” Hirsch writes.
Schools talk about “grade level” reading skills. This makes sense for decoding skills, but not reading comprehension, Hirsch argues. Students can comprehend a reading passage if the content is familiar, but struggle if it’s unfamiliar. ”
For understanding a text, strategies help a little, and knowledge helps a lot,” Hirsch concludes.