Buried deep in the report on the 2009 NAEP science assessment is what is likely the key to raising science achievement (and achievement in other subjects, for that matter). Past scores of data on race/ethnicity, state/jurisdiction, parental education, gender, school location and the rest, is a chart—figure 46—that shows how much simply taking more science courses improves student performance:
What they mean by “coursetaking category” is that they broke down 12th grade student performance according to how many (and what type of) science courses students took. The bottom bar on the chart indicates the performance of students who took just one science course in high school (either biology or another science course, most likely earth science). The middle bar shows the performance of students who took biology and chemistry. And the top bar illustrates the performance of students who took biology, chemistry, and physics.
The difference in performance is significant. Students who took both biology and chemistry scored 15 points higher than those who just took biology or any other single science course, and those who took physics in addition to biology and chemistry scored 33 points higher than single science course-takers. A quick analysis shows (see our math and chart below) that this amounts, approximately, to an 11% improvement for each additional science course taken. So students who took three science courses scored 22% higher than those who took just one.
The great disappointment—and the key reason, NAEP’s data suggests, for poor overall student performance on the science assessment—is that so few students are taking enough science classes. Just one-third of 12th graders who took the NAEP had taken biology, chemistry, and physics. Thirty-eight percent had taken two courses and 28% just one.
So why doesn’t this finding—that taking more science vastly improves student performance on the NAEP—driving the discussion of the science NAEP scores? The course-taking data is relegated to the 9th paragraph (of 12) of the National Assessment Governing Board’s press release and page 50 of its 79-page report. And NAGB didn’t even bother computing the percentage gains associated with taking additional science courses. As far as we can find, no one who has written about this report thus far has even mentioned the course-taking data.
For decades, our discussion about student performance has revolved around data points (race, location, etc. as listed above) that are irrelevant to what actually improves student achievement: increasing student knowledge. It is time to put the content of education at the center of the reform discussion. The longer content, course-taking, and curriculum remain on the sidelines, the further our students and our nation will fall behind.
Lynne Munson
Click here for more Common Core commentary on NAEP.


Is it not also plausible that students who take more science courses have an aptitude for science, and are therefore likely to perform better on tests?
Sue,
Yes, it is plausible. And yet I still believe all students have an aptitute for science and that when challenged with relevance and rigor will succeed beyond their own expectations. As with math, experience with more advanced course work produces higher levels of achievement.
The NAEP report suggest that when students take more years of science they score higher on the science assessment. This is not an unexpected result. The question becomes, why do so few students in the United States take science? Approximately 30% high school graduates earn credits for all three subjects: Biology, Chemistry and Physics. But most importantly these subjects are single year courses. The Common Core report, “Why We’re Behind” finds the countries the outperform the US in science offer multiple years of a subject. In Japan students take 3 years each of Physics and Chemistry. The PISA results from 2010 found that students from Shanghai-China significantly outscored the US in science. The education system in China offers students 3-5 years of each subject Biology, Chemistry and Physics.
The Common Core should not only include content standards but standards on the amount of time a subject is offered. In the sciences, the amount of time should be expanded considerably to match other high performing countries.
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[...] of the rest of the liberal arts. But it’s true that our students’ science knowledge falls far below where it should. And, even for those of us non-scientists, this is problematic. We sift through the latest [...]