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.