Sunday, September 11, 2005

A Recommendation for Science Teaching: Break Down Barriers Presented by Textbook Chapters

There is something that truly bugs me about science textbooks – chapters. In my previous post, I argue that the way we teach science, particularly in middle school and high school, can be misleading to students in the sense that science is made up by a bunch of segregated, unrelated set of disciplines such as biology, chemistry, and physics. While it is undoubtedly important to learn fundamental concepts and principles within a single discipline, rarely do students become acquainted with how science is now done in the real world, which is more and more frequently collaborations consisting of experts from a variety of technical fields where the focus is on the overlap and connections between disciplines. A related problem comes about within a single discipline itself. That problem is the lack of connection and continuity between concepts and principles as presented in traditional textbook chapters.

In a 2002 article I had published in The Science Teacher (December issue, pages 44-47, entitled “Chapterless Science”), the main high school journal published through the National Science Teachers Association (NSTA), I begin:

“When I began teaching high school physics seven years ago, I thought I had some idea of what I was doing. After all, with a doctorate in physics I was confident I knew the material. The textbook, course syllabus, and accompanying laboratory and test bank books outlined exact chapters to teach and labs to perform. However, by the end of the first semester students were not getting the most from the course.

Students were not connecting concepts that were clearly related but presented in different chapters. Students seemed to memorize terms and equations for the chapter tests. When we got to a section of a new chapter in which students had to recall ideas from a previous chapter, many had already forgotten what they had memorized for the short term.

After questioning students about why they were taking this approach, they said they assumed material from each chapter was a separate piece of physics. Because the books separated the material, students were not connecting chapters together to form a single, coherent picture of physics.”

The feedback from students was a sort of epiphany for me when it comes to teaching science. Just as many students get the impression that there are no connections between science disciplines because of the way we completely separate them by courses, within an individual course there is a common impression that a discipline is made up of a series of disconnected set of ideas and topics, because they are separated by chapters. Many students go through their schooling thinking that they need to ‘learn’ a subject by memorizing single ideas from single chapters, without attaining a level of fundamental understanding we want to see where fundamental principles can allow one to make connections between a wide variety of topics (i.e. chapters).

For instance, in a physics class, as students are studying the effects of force in general, I include discussions of all types of forces. We consider springs, friction, centripetal force, gravity, electric forces, and magnetic forces, all within the first few weeks of class. All these topics typically have their own chapters well into the textbook. (For example, one textbook has friction in chapter 4, centripetal force in chapter 5, gravity in chapter 12, springs in chapter 13, electric force in chapter 22, and magnetic forces in chapter 28.)

Although I do not go into great detail with all of the examples of force when they are initially introduced (but this also provides a preview of things to come), students learn that connections exist between many different types of forces relevant to a wide variety of phenomena. The consequences, behaviors, and descriptions of the different forces all can be fundamentally understood with the same basic rules. Even though the appearances of various forces can be dramatically different, students learn that they can begin to understand nature at a new, more fundamental level. In addition, students begin to develop the mentality of scientists, looking for patterns to make connections to different situations to make sense of the world, making predictions, and solving problems using fundamental principles. This technique is a powerful way to begin building critical-thinking skills in students.

Some other examples from my classroom include studying the many similar motions that have common connections. For instance, when we study circular motion, a common demonstration and lab includes twirling an object tied to a string over our heads. The concept of centripetal force is then introduced. Typically, other examples in the chapter covering centripetal force include loops in roller coasters, curved roads, and perhaps airplanes diving into circular paths. But I’ll also include orbiting satellites, electrons orbiting around a nucleus, electric charges moving in circles in magnetic fields, pendulum motion, and so on—all of which are spread throughout the textbook in many different chapters. The students pick up the information quickly because earlier they were introduced to the relevant forces and principles for all these examples. The case of circular motion simply reinforces deeper connections and similarities between all these seemingly different phenomena. Even if we do not cover specific problems or experiments dealing with the topics in later chapters of the book, at least the ideas and principles have been introduced.

As with science disciplines seemingly being unrelated to most students because of artificial barriers we place on them by having them taught in separate courses, we end to do the same thing within single disciplines by using traditional chapter-based texts and chapter-based curricula. The interconnectedness of seemingly different phenomena and principles can be lost to students unless we help break down such boundaries and barriers.


Larry Dunbar said...

Hi Vonny,
I looked at some other blogs to see what they use to stop Spam. I found that on Colounsbury’s blog the commentator has to answer a question before signing in. I was hoping some of your readers had something else to add. Spam is annoying but I hope you don’t give up on your blog because of them.
In college I found most of my textbooks well written and the fact that one chapter supported the next as a given. I realize there must have been students that didn’t see this connection. However, what I found that made the most difference in connecting the chapters of the book was how the student prioritized his or her life. What the student wanted out of life, school, a certain class, chapter, or book depended on how high on the list of priorities the lesson was. Sometimes it came down to having time to read and understand one chapter from one class or reading two chapters from two different classes and not understanding either. The students that seemed to do the best were the ones who knew which decision to make. These decisions did not mean that the student would retain the knowledge from one chapter to the next, because they may have had a different priority during the last chapter.
Perhaps this is what makes our school system different, than those of other nations. While the instructor is both encouraging and demanding perfection, the system is making the student make choices that will last them a lifetime.

Erica said...

One of the things I noticed in my teaching job over the summer was that a lot of my students had a very linear, sequential style of learning. They seemed to grasp ideas most thoroughly if they thought of each topic as a separate, self-contained concept, because when I tried to connect the topics, they started to mix them up.

For example, I tried giving them the electron orbiting a proton example for both circular motion and electrical force, and after that I saw a lot of people mixing up the circular motion ideas and equations with the electrical force ideas. However, the students said they had less trouble when I confined the types of problems I explained to them to one particular part of physics because they could "catagorize" the different concepts and did not confuse them as easily.

I realize that separating different topics that are fundamentally related is not the best way to teach physics, but how do you reconcile the interconnectedness of physics with the fact that many students learn in a very sequential manner? The fact that I had this problem may just be due to my inexperience as a teacher, but I would be interested to hear your opinion.

Schiffman said...

I definitely appreciated your more integrated style of teachign when I attended your class, and that to some extent I agree with you. Classes should be taught like that. However, the segmented nature of textbooks seems to also be important. It allows students to focus in on a specific area that is troubling them, or that the teacher did not teach so well (not that I ever had that problem with you). I believe that while teachers should strive to integrate far flung aspects of science into there curriculum. The textbooks shoudl only be an aid or reference to help a student on a difficult part.

However, one difficulty that arises when an integrated approach is used occurs when students are taking a standardized test. I remember you attempt to compartmentalize everything right before the AP tests-dividing our curriculum into a small set of basic problems. If one's goal is simply to teach to the test, then a compartmentalized approach is definitely the path of least resistance.

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