Will Depth Replace Breadth in Schools?

Will Depth Replace Breadth in Schools?

If our nation’s high school teachers had $20 for every time they had to endure the Depth vs. Breadth debate, they all would have retired to mansions in West Palm Beach.

The debate goes like this: Should they focus on a few topics so students have time to absorb and comprehend the inner workings of the subject? Or should they cover every topic so students get a sense of the whole and can later pursue those parts that interest them most?

The truth, of course, is that students need both. Teachers try to mix the two in ways that make sense to them and their students. But a surprising study — certain to be a hot topic in teacher lounges and education schools — is providing new data that suggest educators should spend much more time on a few issues and let some topics slide. Based on a sample of 8,310 undergraduates, the national study says that students who spend at least a month on just one topic in a high school science course get better grades in a freshman college course in that subject than students whose high school courses were more balanced.

The study, appearing in the July issue of the journal Science Education, is “Depth Versus Breadth: How Content Coverage in High School Science Courses Relates to Later Success in College Science Coursework.”

The authors are Marc S. Schwartz of the University of Texas at Arlington, Philip M. Sadler and Gerhard Sonnert of the Harvard-Smithsonian Center for Astrophysics and Robert H. Tai of the University of Virginia. This is more rich ore from a goldmine of a survey Sadler and Tai helped organize called “Factors Influencing College Science Success.” It involved 18,000 undergraduates, plus their professors, in 67 colleges in 31 states.

The study weighs in on one side of a contentious issue that will be getting national attention this September when the College Board’s Advanced Placement program unveils its major overhaul of its college-level science exams for high school students. AP is following a direction taken by its smaller counterpart, the International Baccalaureate program. IB teachers already are allowed to focus on topics of their choice. Their students can deal with just a few topics on exams, because they have a wide choice of questions. AP’s exact approach is not clear yet, but College Board officials said they too will embrace depth. They have been getting much praise for this from the National Science Foundation, which funded the new study.

Sadler and Tai have previously hinted at where this was going. In 2001 they reported that students who did not use a textbook in high school physics—an indication that their teachers disdained hitting every topic — achieved higher college grades than those who used a textbook.

Some educators, pundits, parents and students will object, I suspect, to sidelining their favorite subjects and spending more time on what they consider trivial or dangerous topics. Some will fret over the possibility that teachers might abandon breadth altogether and wallow in their specialties. Even non-science courses could be affected. Imagine a U.S. history course that is nothing but lives of generals, or a required English course that assigns only Jane Austen.

“Depth Versus Breadth” analyzes undergraduate answers to detailed questions about their high school study of physics, chemistry and biology, and the grades they received in freshman college science courses. The college grades of students who had studied at least one topic for at least a month in a high school science course were compared to those of students who did not experience such depth.

The study acknowledges that the pro-breadth forces have been in retreat. Several national commissions have called for more depth in science teaching and other subjects. A 2005 study of 46 countries found that those whose schools had the best science test scores covered far fewer topics than U.S. schools.

Some commentators have complained that despite this trend, many U.S. teachers are still rapidly addressing every topic because of the pressure to prepare students for standardized tests. But “Depth Versus Breadth” suggests such pressure is losing its influence, if it ever had any. Sixty-four percent of the college students surveyed (including 55 percent of biology students, 73 percent of chemistry students and 66 percent of physics students) said their high school science courses spent at least a month on just one topic.

Those who want to fight about this will be interested in the topics that got the most attention in those high schools: cell biology in biology, the periodic table in chemistry and mechanics in physics. The topics most neglected were history of biology, biochemistry and history of physics. Also on the lower end of the attention scale were evolution, nuclear reactions and relativity.

You see the problem? Science education has become a politicized subject. Any teacher — or program like AP — that decides to go deep is going to make enemies. That is one reason why textbooks have tried to cover everything and why some educators still endorse breadth.

Trevor Packer, the College Board vice president who directs the AP program, seems aware of the controversies that await him. He says that while the majority of AP teachers have indicated support for reducing breadth in AP science, he anticipates some resistance from teachers who like breadth because it offers the chance of connecting in some way to every student. “It will be very important to draw upon findings such as these to help teachers who prefer the current course understand why it is so essential for us to change AP so that teachers and students have more time to really investigate in great depth a smaller number of topics,” Packer said.

What surprises me is the study’s suggestion—it does not address the issue directly—that introductory college science courses are rewarding deep learning. I have been suspicious of national commissions full of college professors that demand more depth in AP courses when AP courses are supposed to mimic introductory college courses, which have not seemed very deep to me.

Trying to balance depth and breadth, how can we tell when we go too far? A lot of people in science education seem to be jumping into the deep end of the lake. That’s fine. It may prove to be a wonderful adventure for our students. But down there in that murky water we may find things we don’t like.

 

Jay Mathews

Columnist — Washington, D.C.

The Washington Post