The number of books in the home makes a huge difference for student performance in math and reading. That's the conclusion I reach after examining NAEP long-term trend data.
NAEP stands for National Assessment of Educational Progress and is often referred to as "The Nation's Report Card." In recent years, the National Center for Education Statistics has provided a very useful data tool that allows citizens to analyze the results for themselves.
Using long-term trend data in mathematics and reading, I looked at the difference in performance between students with ten or fewer books in the home vs performance of students whose families had 26-100 books.
For students ages 9, 13, or 17, and in both math and reading, the students with more books at home scored between 21 and 35 points higher. How big a difference is that? Well, the average 13-year-old scores 38 points higher in reading than the average 9-year-old; the average 17-year-old scores 26 points higher in math than the average 13-year-old. So differences of 21 to 35 points are like differences of 2 to 4 years of learning.
Well, you say, number of books in the home is probably just a marker of socioeconomic status. For many years I thought so, too, and to some extent we were right. After all, the difference in performance between students eligible for the federal free lunch program (a marker of poverty)and those not eligible ranges from 22 to 28 points on these same tests.
But the data tool allows you to separate out different factors. It turns out that even after removing the effects of poverty, having more than 25 books in the home versus fewer than 10 books accounts for a difference of from 12 to 28 points (1-4 years) in math and from 20 to 28 points (2 to 4 years) in reading. For older students, having even more books in the home becomes important: there's up to another 14-point boost in scores for having more than 100 books.
What does this mean? It means that having books at home does a lot to counteract the persistent effects of poverty on student performance. That's why programs like Raising Readers, Reading is Fundamental, and Reach Out and Read are so important.
My next post will have more to say about the connection between books in the home, scholarly culture, and student educational success.