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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.

By Washington Post editors  | February 27, 2009; 3:00 AM ET
Categories:  Trends  
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Count me on the "depth" side. Especially in science. The most important thing that people can learn in high school science is how to approach the world scientifically -- how to think logically, what is the scientific method, how to see the universe from that quintessentially scientific angle (something which is sorely lacking in probably 95% of the population). A generic survey course -- just learning certain rules and laws, without a comprehensive understanding of why those laws are what they are and how they all fit together -- is relatively worthless for long-term understanding of the subject. It just leaves the impression of all of these complex rules that don't make any sense and that no mere mortal can actually figure out.

I am reminded of my high school history courses. From my own experience, they were all just a serious of names and dates strung together; there was no perspective, no sense of social or religious or economic or environmental factors that lead from one to the next. My ability to do well on the test hinged on my ability to memorize apparently disconnected facts. Not surprisingly, I forgot all of that the minute I stepped out of the classroom.

My chemistry class, on the other hand, walked us through all of the equations -- not just how to do the computations, but how different chemicals reacted with each other to form entirely new compounds, how it worked, what it meant -- how you could figure out from this one reaction what might happen in this other reaction, and then how you can test your hypothesis to figure out whether you were right. It left me feeling not only competent in that area, but also confident that I could then use the same approach to understand other areas (well, except for galvanic cells -- they freaking killed me, don't ask me why). I adored that class -- got a 5 on the AP, and almost majored in chemistry in college.

It's kind of like law school. They don't actually teach you much about the law -- at least, not much about the law that you're going to need to know when you get out and practice. But they teach you how to think like a lawyer -- how to find what you need and how to analyze it, so that once you do get out there, you can pick up the specifics of your particular area pretty quickly.

Posted by: laura33 | February 27, 2009 9:46 AM | Report abuse

I teach 10th graders chemistry. I have a difficult time acheiving depth or breadth because of the lack of math and reading skills my students come in with. I spend more time teaching them algebra then chemistry in some of our units. I would say our focus for HS in VA anyway are the SOL's - naming/writing formulas, periodic table, states of matter (gas laws) and mole calculations - no time for the biochem or nuclear. We have certain essential knowledge we must cover and cover well, a lot of the other stuff is unfortunately "fluff" - nice to know but not essential. Since the SOL is in May and not truly at the end of the course in June and since we start in September, every day is essential learning.

Posted by: annwhite1 | February 27, 2009 12:19 PM | Report abuse

I'm in the 'other' category.

Elementary school children need to KNOW the basics. Rushing through the multiplication tables so you can go onto bar charts is a mistake.

Beyond the basics there is plenty of room for depth/breath. Too often children are rushed through things and never get a chance to catch up.

Posted by: RedBird27 | February 27, 2009 12:21 PM | Report abuse

For the record, the mansions are in Palm Beach, not West Palm Beach.

Posted by: Rob63 | February 27, 2009 12:22 PM | Report abuse

Need both. Breadth for foundation and to expose students to different aspects of the subject. You never know what a student will be interested in and possibly pursue in terms of a postsecondary education or career.

Depth is also important to engage a student and teach critical thinking and analytical skills.

Maybe go over everything and then allow students to do independent study.

Posted by: mediajunky | February 27, 2009 12:36 PM | Report abuse

Of course they want to limit the subjects, because IB is a trojan horse and should be REJECTED across the board.

In places where they are spending $20K/yr on each student, who can justify extra tax dollars to pay for a program from some communist bureaucracy OUTSIDE THE COUNTRY that seeks to brainwash students to their world view?

IB is one of the worst fads or educational scams to come down the pike in a long time. Stupid yuppies are falling for it too.

Posted by: username | February 27, 2009 12:38 PM | Report abuse

I see a substantial problem with the analysis- the measure of success is "success in college."

We need to think long and hard before believing that is the same as "understanding"; or "lifetime productivity." Personally - I think easily available statistics will readily show there is scant connection between grades and real life performance.

My experience with many real life high performers- it's going to be a very personal factor. Some do well one way- some the other; and most infuriatingly, individual A needs deep instruction in topic X, but broad exposure to Y; and individual B - the opposite.

Designing programs so that choice is possible- may be most effective.

Posted by: woodyag | February 27, 2009 12:56 PM | Report abuse

I'll just say I Totally Agree with everything that laura33 posted.

Students can learn a broad survey of science on their own (if they haven't learned it already by the time they reached the class). It's the how's and why's that are best taught in the classroom.

Posted by: VAOrangeFish | February 27, 2009 12:57 PM | Report abuse

Depth is not possible without a solid breadth of foundation which is laid on in elementary and middle school. This method of teaching science in High school is very wrong, where there can be a gap of one or two years before a subject is taken on again.
All 7th,8th, 9th and 10th grade students need to study some elements of Biology, Physics and Chemistry year round. Children who do some basic chem in 8th grade and then are expected to do (college level) chem in 10th grade are disadvantaged because of the gap. They struggle in class and then lose confidence and interest and stop studying science altogether. It has happened in my own family my dismay.

Posted by: rammnam | February 27, 2009 1:17 PM | Report abuse

It seems to be that students need both at different times. For younger kids breadth is more important so that they be exposed to a wide variety of subjects.

Once they reach high school, they can focus on the subjects that will take them into college and then have more depth.

Posted by: mosere | February 27, 2009 1:42 PM | Report abuse

Ideally it would be both. Having to pick, I'd go with depth. As a math teacher, I have argued against the rush to push kids into Algebra 1 in seventh and eighth grade. We are sacrificing depth of knowledge to accelerate these kids.

The lack of depth really shows up when you get to more complex mathematical topics. Kids do not have good basics but yet are being shoved ahead. As an experiment go into an eighth grade algebra 2 class and ask them to solve a quadratic by completing the square. Most of them won't be able to because they don't have good basic math skills.

Posted by: ggartner | February 27, 2009 2:16 PM | Report abuse

What bothers me most is when the "non-professionals" start telling the "professionals" to teach.

As a math instructor, it always boggles my mind that as educators, there is always someone OUTSIDE of the classroom dictating what to teach or not teach. No other profession comes readily to mind that has this form of interference. We make suggestions to the Police Departments, but ultimately they do what they NEED to combat crime and ensure safety. We as laymen definitely don't dictate how a fireman should battle fires, and most assuredly we outsiders do not tell judges or lawyers how to interpret law.

In my humble opinion, and we all clearly have them, we, educators should have this debate...thank you parents and other representatives for your input and advice, but ultimately, we have to do the teaching and would prefer if you LET US PROFESSIONALS do our jobs.

Posted by: WTCouncil | February 27, 2009 3:04 PM | Report abuse

As the parent of a "science" student, I wish my son was here commenting because he would have lots to say about depth and breath of science learning.

I can only speak from my own perspective of raising a child who lives and breathes science.

In third grade my husband and I were sent to the principal's office because my son refused to answer questions on his science tests because he thought the questions were "stupid." When he tried to answer a question, laying out the process of photosynthesis, the teacher told us that it was the "wrong" answer because she was only looking for the word "oxygen" in the students' answers!

Once he got to high school, he breezed through every science class offered in the curriculum. Again, he was disappointed because most of what he was learning he thought was "superficial" and he had learned much of it "along the way."

When he finally entered college he finally was "challenged." Thankfully, he was introduced to subjects and topics that were never studied or "touched" in high school.

His first two years as an Aerospace major were frustrating because he studied no aerospace. But now, he's on a cloud, finally learning in depth about the area of science he loves. As a bonus, he decided to take a nuclear class and found he loved that too. Now he's majoring in Aero and working towards a certification in nuclear.

Science ducation is NOT Rocket Science. I think the seeds to inspire students towards the love of the sciences should begin, as some have suggested at the elementary school level. Those seeds should be big and bountiful.

I believe while children are small, that's when they are the most inquisitive about science and that gives educators the leg up in motivating children to learn about this important subject.

When my adult daughter studied Earth Science in 8th grade, she came home one day and said she now understood the dynamics about the ocean's waves - something until that day she took for granted and understood little about. She was enlightened and afterwards, enjoyed learning everything she could about the Earth.

There's no magic involved in learning about science. Children are naturally inquisitive about science. Engaging them deeply at an early age can make the challenges of teaching them about many different topics will become easier as long as the foundation is set at an early age.

Posted by: 1voraciousreader | February 27, 2009 5:03 PM | Report abuse

to WTCouncil:

I'm also a teacher who understands your opinion about hyper-involved parents, but I have to respectfully disagree that we should simply be left to do our jobs.

Parents should have the last word. It's their kids who we're teaching, and they should have some control over the content. We can tell them that we disagree, but ultimately it's up to them.

Posted by: mikecapitolhill | February 28, 2009 9:11 AM | Report abuse

I'm with AnneWhite above. In each grade teach students what they will need to succeed in the next grade. For high school, if we don't know what colleges will expect prepare students to earn credit on AP and/or IB exams.

Finally, have a large part of teacher assessment be based on how well teachers in the subsequent grade believe students enter prepared to succeed. My impression is that students who can't do algebra struggle in calc. and that students who can't do simple division and multiplication can't succeed in algebra. If I'm right, we can drop bar graphs and probability until students master multiplication and division.

Posted by: mct210 | February 28, 2009 10:54 AM | Report abuse

The answer to breadth vs. depth is "Yes". One needs to start by deciding what the goal of a course, or sequence of courses is to be. What must a student understand from a course, what should a student understand from a course, what would be nice for the student to understand from a course.

However, we have a problem. What is the definition of "depth"? Whatever definition we come up with, I'm certain of one thing. No kids graduating from high school will know anything in depth. Why?

Knowing anything in depth takes passion, single-mindedness and decades of work. This depth is not going to be achieved, or should be achieved in high school, or even four years of college. Maybe parents, teachers, and kids are fooled into thinking otherwise, but it is not true.

What's that line? "Hire a teenager -- while they still know everything".

Posted by: LarryW1 | February 28, 2009 3:14 PM | Report abuse

Your attitude towards parents is very paternalistic. I'm not going to take everything a teacher says as Gospel. Don't forget that as a taxpayer, I'm paying your salary!

Posted by: CrimsonWife | March 1, 2009 4:49 PM | Report abuse

I would definitely choose breadth over depth. Let me elaborate.

I'm currently a junior in high school. I'm taking AP Euro and AP Comparative Politics. In these classes, I've learned quite a bit. My point here is that I would much rather learn more than deeply. That's what college is for. A student learns the basics and the overviews of history in high school, then learns about the specifics in college if they're interested. What's the point of going into depth if students aren't interested?

I would much rather learn a good deal about European overall rather than every battle and skirmish in the Hundred Years' War. Or about the exact GDP changes of Britain during the industrial Revolution. Obviously, it would be nice to have a good balance between breadth and depth, but if I had to choose, I'd pick breadth.

I think many might choose depth because people say"quality over quantity". But I think that college is the time for depth while high school is the time for breadth.

Posted by: JohnS13 | March 1, 2009 7:54 PM | Report abuse

To continue, primary students also need to explore a wide range of topics in social studies and science. These are the topics that get children, especially boys, excited about learning and make them want to pick up a book or work on a project.
Our school has been a Reading First(ONLY) school for three years now. My children barely get any science or social studies. There isn't time to delve into topics such as sharks, snakes and maps that make their eyes light up and have them snatching up multiple library books on the subject. This is how we inspire future scientists and historians. I miss seeing their excitement and the sparkle in their eyes as they learn about topics that truly interest them. Can't we have a balance that has high expectations for our children, challenges that encourage them to work up to their ability and topics to inspire them to want to be life-long learners? There must be a way.

Posted by: NanceAZ | March 2, 2009 8:38 PM | Report abuse

We used to call this "post-holing" when I taught Western Civilization. Pick a theme (ours was the growth of the ideal of individual liberty) and use the theme to tie together the diverse elements of everything from Sumeria to the European Union. Along the way,dive deep into the watershed events that change the thinking about how people and their governments interact. Lots of time with political and economic philosophy, tied into the tides of history. Engaging, wide ranging and still in depth where necessary. The students were given opportunities quarterly to do individual research projects, and the semester and final exams were 25% multiple choice, 25% short answer and 50% essay. Of course, this was before NCLB and our current enlightened focus on standardized testing....

Posted by: NBCT2001 | March 3, 2009 9:05 AM | Report abuse

I think that maybe this study shows the need not only for in depth teaching but also to have a longer school year. The US spends less time in school (days and hours) than most other countries. (Japan, etc) We are only in school 180 days out of 365. So half the year in school and the other half out. We must address this if we as a nation are going to be successful.

Posted by: dho7993186 | March 3, 2009 10:15 AM | Report abuse

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