However, U.S. schools, especially those that serve low-income children, have moved in the opposite direction. Educators have felt pressure to cut time for science, social studies and the arts in order to carve out more time for reading and math, the two subjects that are tested annually by every state and by which schools are judged. During reading class time, many schools emphasize skills over content, asking children to practice comprehension strategies on short reading passages, rather than reading a whole novel. Critics say this has hampered the ability of children to build a strong foundation of background knowledge at school and has impeded their reading comprehension.
“The major factor that’s the cause of achievement differences in low and high income students turns out to be their level of general knowledge,” said David Grissmer, a research professor at the University of Virginia and one of the lead authors of the study. “It’s geography; it’s history; it’s science; it’s cooking; it’s athletics, whatever that broad knowledge is about the world we live in. It comes from lots of different sources, sometimes from families, sometimes communities, sometimes from school. It’s the experiences kids have that build that general knowledge, which really provides the particular advantage that we see for higher income kids. I don’t think it completely accounts for it, but it accounts for more of that difference than I think most of us ever thought.”
It’s nearly impossible to test different instructional approaches in real classrooms. Teachers can teach only one curriculum at a time – often after years of training and practice to implement it correctly – and so it’s not practical to randomly assign some children to learn a different way in the same school. One can study the students at schools that have adopted the Core Knowledge curriculum, but it’s hard to know if the students who attend these schools would have scored just as high in reading if they had been taught the usual way at a traditional public school.
In this study, the researchers copied a method used by charter school researchers. They identified nine charter schools in Colorado that had adopted Hirsch’s Core Knowledge curriculum. They were popular schools with more applicants than seats and so the schools conducted lotteries to admit students. Researchers tracked students who won kindergarten seats in 2009 and 2010, and monitored their test scores through sixth grade, comparing them with students who also wanted to attend these schools but lost the lottery. The lottery losers attended a variety of other schools, from traditional public schools to private schools to other charter schools. Some postponed starting kindergarten that year. Students who attended one of the Core Knowledge charter schools for at least four years had much higher reading scores than lottery losers who did not attend, and the advantage lasted through at least sixth grade.
A huge complication in this study was that Colorado families had applied to many schools as part of the state’s school choice system. Half of the approximately 1,000 lottery winners chose not to claim their kindergarten seats and opted to attend other schools. In other words, researchers lost half of their study subjects. We don’t know how these children would have fared had they attended the Core Knowledge schools. The results might have been different.
In theory, knowledge building and reading achievement ought to be a virtuous circle, where children with greater background knowledge should be able to grasp more of what they are reading, which, in turn, helps them learn more and build more background knowledge and become even better readers. However, in this study, researchers detected the full benefit of the Core Knowledge curriculum immediately in third grade, the first year that children are tested at schools. The advantage for Core Knowledge students did not increase further in fourth, fifth and sixth grades.
More than 600 schools across the United States have adopted all or parts of the Core Knowledge curriculum, according to the Core Knowledge website, and, what we all want to know, is how well it’s working in low-income public schools. As those results come in, it will be a welcome addition to the debate on how to teach reading, which, in my opinion, has been excessively focused on teaching phonics to children in kindergarten and first grades. That’s important, but becoming a good reader, with strong comprehension skills, takes a lot more. What kids need to know may prove to be critical. Of course, it will open up a whole new political debate of what content knowledge kids should be taught, and in our political times, that won’t be easy for communities to sort out. Procedures and strategies are easier. Content is hard.
The study, “A Kindergarten Lottery Evaluation of Core Knowledge Charter Schools: Should Building General Knowledge Have a Central Role in Educational and Social Science Research and Policy?” was funded by the Institute for Education Research (an arm of the U.S. Department of Education), the National Science Foundation and two private foundations. One of them, the Arnold Foundation, is among the many funders of The Hechinger Report.