DURHAM — Wake County is grappling with a question that has been asked across the country: Should more students take Algebra I in eighth grade? Put it off until ninth grade, and there's little chance you can take calculus in high school. Take it in eighth grade and do badly, and there goes your strong foundation for higher math courses.
Around the nation there has been a movement afoot for at least a generation to introduce students to algebra in middle school rather than high school. In the 1980s, about 1 eighth-grader in 6 enrolled in algebra. Today, the fraction has doubled, to 1 in 3. Two of North Carolina's three largest school districts joined the movement a decade ago. Their experiences offer important and relevant lessons for Wake County today.
Together with our colleague Charles Clotfelter, we studied the consequences of moving Algebra I to eighth grade in these districts. Our findings suggest that algebra acceleration might do more harm than good, unless students begin preparing well before they enter eighth grade.
Before talking about the good evidence, it's worth taking a moment to talk about the bad evidence. Many studies have documented a tendency for students who take algebra in middle school to go on to accomplish all sorts of wonderful things. They are more likely to do better in their high school math classes, more likely to go to college and probably more likely to win Nobel Prizes, too.
The quick - but inaccurate - takeaway message from this evidence would be that all students would be better off taking algebra at an earlier age. That's an incorrect conclusion because most students who take algebra before high school were already scoring well above average on math tests as early as third grade. So it isn't accurate to attribute their later-life success to middle-school algebra - they just happen to be the type of student who will do well in life whether they take the course early or not.
To get better evidence on the question, we needed to look for situations where otherwise comparable students are treated differently - one assigned to take algebra in eighth grade, the other in ninth. We can then more accurately determine whether the timing of algebra makes a difference by tracking those students as they proceed on through high school. Fortunately, recent district policy changes in North Carolina provide us with exactly this type of situation.
About 10 years ago, the Charlotte-Mecklenburg and Guilford County school systems embarked on algebra acceleration initiatives quite similar to what is being proposed in Wake County. Students whose math performance - as measured by the state's own end-of-grade tests - might best be described as "average" were taught algebra in eighth grade instead of ninth grade.
These are exactly the type of students who would be affected by Wake's proposed initiative; our calculations indicate that such students have about a 70 percent chance of passing the state's end-of-course test in algebra.
To figure out whether students are better off when they take algebra a year earlier, we compared those who went through eighth grade just before the acceleration to those born a year or two later.
The results were sobering. The students placed in algebra in eighth grade performed much worse in that course, and their chances of staying on track to complete a college-prep math sequence by the time they finished 12th grade declined significantly.
The biggest problem for the accelerated students was geometry. The state's standard curriculum for eighth-grade math - the course that accelerated students skipped - includes some introduction to geometric concepts. Students placed directly in algebra forgo an opportunity to solidify their understanding of geometry.
Teaching algebra in eighth grade is clearly not bad for everyone. Indeed, our own evaluation of Charlotte's 2002 math reform shows that very strong students can do well even if they take algebra in seventh grade. But for students whose math performance lies in the average range as of sixth or seventh grade, it appears best to hold off on algebra until high school.
Our results do not mean that Wake County should give up on the idea of accelerating the math curriculum. It does mean that, in the absence of other curricular change, the school system should be very picky about which students are accelerated.
In the long run, the best policy for Wake and the state as a whole may be to restructure courses before Algebra I to ensure that more students are ready to thrive in algebra in eighth grade.
Helen F. Ladd and Jacob L. Vigdor are professors in the Sanford School of Public Policy at Duke University.