Cutting Through Right-Wing Spin on Public Education

When the Going Gets Tough, Privatization Proponents Get Paul Peterson

Monday, August 7, 2006
People For the American Way
By Kevin Franck

Let's say that someone invented a pill that supposedly makes children grow faster. To measure its effectiveness on children from two different countries, you would assemble a sample group of each and measure their growth over time. But what if the children in one of the countries already tended to grow at a faster rate? This would certainly skew your results. The question would be how to isolate the effects of the pill by accounting for pre-existsing differences in growth rate.

The authors of a recent education study faced this very question when they tried to compare the effectiveness of public schools and private schools. Conducted by the National Center for Education Statistics, the study compared the test scores of students in different schools and initially found that private school students scored higher. But they had not yet accounted for demographic characteristics – e.g. parental income and education level, the number and quality of books found in the home, etc. – that affect student test scores irrespective of the quality of school attended. For instance, children in private schools tend to come from wealthier and more educated families and therefore tend to score higher.