Thursday, 22 August 2013

07:58 – The main headline in this morning’s paper was N.C. students not as ‘college ready’ as peers

The results from spring 2012 are in. The average score of North Carolina public high school juniors taking the ACT dropped from 21.9 the previous year, which was a full point above the national average, to 18.7, which was dead last. In fairness, the article did point out that this drop was expected, and why. In 2011, only about 20% of public high school juniors took the test; in 2012 100% of the juniors were required to take it. Obviously, the average is going to be much lower if you test all students than if you test only the top quintile.

The article also pointed out that white and Asian students have higher average scores than black, Hispanic, and American Indian students, but it failed to draw the obvious conclusion. Comparisons between states are meaningless unless those results are normed to take into account both the percentage of students who take the test and the racial makeup of the tested population. States whose students are primarily white and Asian are going to have better averages than states with significant percentages of black, Hispanic, or American Indian students.

Less obviously, the percentage of students in a given state who are home-schooled has a disproportionate effect on average public high school test scores. Home schooled students are, on average, much brighter than public school students. There’s self-selection going on. Homeschooling drains the best students from public schools. I don’t have the data at hand, but I’d be willing to bet that if homeschooled students from across the US were grouped and treated as a separate state, their average scores would put them not just first of all states, but far, far above whichever state ranked second.

Most colleges and universities now recognize the reality that homeschool students are the best of the best. Only a few years ago, many colleges were leery of homeschool students because they lacked public school transcripts. Now, many colleges and universities, including many of the most prestigious, are actively recruiting homeschool students.


13:49 – Oh, yeah. A couple of very important things about homeschooling and standardized test scores that I forgot to mention in my earlier post. First, students who’ve been homeschooled for only a year typically average 59th percentile on test scores. Students who’ve been homeschooled for several years or longer typically average 90th to 93rd percentile. Second, for homeschooled students, racial disparities in standardized test scores begin narrowing quickly even after only one year of homeschooling. After two or more years of homeschooling, racial disparities in standardized test scores essentially disappear. That is a truly damning indictment of public school systems.