Using Historical Explanations
Teaching How Science Works
by Jean Beard
As science has become more dependent on magnification and sophisticated chemical and physical analysis of the natural world, more of our conclusions and explanations of how things work must be accepted based on the authority of others. Much scientific knowledge has become abstract. A danger in teaching science as a body of knowledge is that such acceptance of what others have figured out encourages good minds of all ages to ignore their own observations and intuition.
We all make observations that dont jibe with currently accepted knowledge. For instance, both the sun and the moon appear to rise in the east and set in the west. So they both appear to orbit the Earth, but among the first things we teach about the solar system is to make the point that only the moon orbits the Earth. Children, who are often very literal, may struggle with counterintuitive ideas or simply ignore them. In one of my literal periods at age four or five I remember being disappointed when I realized that it could rain on Sun-day.
Many ancient explanations are based on non-technical, but careful, observations. These phenomena are still observable and indeed are part of the first knowledge gathered by young people. A number of these observations can be used as the basis for learning how science works.
Imposed limits on learning
Children are inherently curious. What they learn about their world comes from their own perceptions and it is combined with information added by others. The others are mostly adults who, from the childs perspective, also provide a variety of rewards and punishments. For the child, it becomes important to agree with the authoritative adults, parents and caregivers, and later, teachers in school. Students often explore to find patterns, but stop searching when their new explanation seems to please an adult. Many times the adult explanation does not satisfy the young persons curiosity nor provide a satisfactory end to the search. This can be an early source of misconceptions.
In early schooling, students are taught the prevailing language and its communication patterns. The symbolsletters and numeralsare precise. Letters are combined to make words with correct spellings and they are strung together in appropriate groupings to convey limited meanings. Numerals are manipulated to gain specific results. And by this regimentation primary grade students are persuaded to accept adult directions and explanations and to ignore other possibilities that may occur to them. This results in acceptance, without question, of adult products such as print and other media.
Schooling in science
If science is presented in primary grades as an exploratory activity, students should be allowed to arrive at their own conclusions. However, what often happens is that students mess around with the provided materials long enough to figure out what the teacher wants them to learn from the activity. All too often the problem posed comes from the teacher, and would not have occurred to the students. And so curiosity and science are separated for most students by the time they reach intermediate grades and middle school.
The incoming middle school student usually accepts what is in the science text, because it is in the book, not because it makes sense. Too often the texts and lessons from earlier grades provide isolated facts to be memorized. These specific facts need to be associated with the concepts they support to foster understanding of how the natural world works. In order to teach how science is done and to create more scientists and engineers, students schooling needs to foster observation, curiosity, and to require sufficient evidence from authorities for conceptual learning.
It became apparent to me years ago while teaching junior high school science that using previously accepted explanations of natural phenomena can provide a useful review function. The ancient explanations were based on observations available to all because they required neither visual magnification, nor molecular analysis.
Early in my teaching career, as a brief review before the unit test on air, I proposed to seventh graders that if I had come from an ancient time I would not understand their conversation about air. The text chapter was about air and its components. In class demonstrations we had chemically generated oxygen, carbon dioxide and hydrogen as described in our textbook. (Note: These demonstrations are no longer considered safe in a classroom without a ventilating hood.) So the unit test was to be on the chemical components and physical properties of air that they had studied.
To be consistent in my conversation with the students, I adopted the old four-element explanation, but I mentioned only earth, fire and water. My premise to the students was that I didnt understand how they thought there was something that I couldnt see, smell, taste or feel in the empty spaces between us. My rebuttal to each of their explanations was based on this premise or was composed of a lie so bold that they should have had the information to refute it.
To my surprise, and joy, the students became seriously engaged in trying to prove that I was wrong. They begged for time the next day to demonstrate to me that there is air. And the following day they brought in materials to demonstrate the force of air movement by various means, but with our equipment had difficulty making that case that air had mass. Later I learned from teachers and parents that they had asked many others for help in making their case.
The nature of science
The Flat Earth is another example of an old concept that I have used. Intuitively, our own observations support a flat rather than a spherical earth. The earliest recorded explanations for the earth included water on all edges and pillars to hold up the sky. Such descriptions fit our own early, less precise observations. Travel to other land masses and better observations of stellar movements make such explanations less acceptable. There are two sources available to demonstrate how this might work.
The first source is designed to help students decide what makes information acceptable in science. It was assembled to assist high school biology teachers develop student skills for sorting science from alternative explanations that purport to be science, such as creationism. ENSIweb is an online resource for teachers that contains lesson plans and resources for teaching about the nature of science and about evolution. (ENSI was a series of NSF supported institutes called the Evolution and Nature of Science Institutes.) The Web site was developed and is tended by an ENSI alum after the institutes (19891997) were completed. For the first time we have a common format for lessons from many teachers working in different institute groups. We found that many of the nature of science lessons were suitable for younger students. These lesson plans can be found at http://www.indiana.edu/~ensiweb/.
Recent images of the Flat Earth are of a disk with the North Pole in the center, the Ice Wall on the outer edge and the Equator circle half way between. Some claim the United Nations' logo is such an image.
The Flat Earth lesson on ENSIweb asks students, based on their own information, to demonstrate that the Earth is not flat. In the process they sort their own observations from secondary sources. Secondary sources for them include pictures from space that are usually printed on flat surfaces. They also recheck their own observations to determine which do and dont make the case for a non-flat Earth. For instance, the Earths shadow on the moon could be from a flat disk that is round but not spherical. As it turns out most students have not observed a ship appearing or disappearing on the horizon, and so personally have no valid primary observation of a non-flat Earth.
The final part of this lesson encourages students to develop a short list of terms that characterize science. These can vary depending on the class, but must include such things as repeatable and/or testable, natural and tentative. Use of such lists can help students and the class judge the reasonableness of news stories and other public information.
Another concept from this lesson is that science explanations must change when newer and more complete evidence requires a newer and better explanation of natural phenomena. So while the Earth was once thought to be flat, we now know that it is spherical. The early Flat Earthers were using all of the available information. The current Flat Earthers are ignoring valid available observations.
Video of Flat Earth
In Search of the Edge was produced as a fake science video in defense of the current Flat Earth explanation: that it is a disk-shaped earth with the North Pole in the center, and an ice wall on the outer edge. The ice wall is compatible with observations of Antarctica. The video format is similar to the one used in science programs such as Nova. Experts are interviewed to explain the principles of the Flat Earth. The human interest element of the program is the story of Andrea Barnes who is intent on traveling to the ice wall to prove that the Earth is flat, contrary to what she was forced to learn in school. The Flat Earth experts and their explanations are humorous to those who understand the tongue-in-cheek presentations.
While the video is a wonderful spoof, a careful debrief is essential for an audience of people of any age who take what they see on television as fact. The unintended consequences of an incomplete debrief may be selling the Flat Earth concept, a lesson I learned while teaching a college general education science class a few years ago.
A full debrief should include discussion of the evidence provided in the story by the experts and the inferred credentials of the experts. Discussion should get to a listing of qualifications for acceptable authorities such as profession or position appropriate to expertise. Further discussion could provide authenticity-screening criteria for Internet, TV and other media presentations.
In the No Child Left Behind era of more testing, we often only demonstrate learning of factoids rather than understanding of concepts. In other words, it is now more acceptable to teach about what scientists have figured out than to teach how science is done and why it is fun.
Skeptical curiosity and insistence on evidence are essential to the process of science. Young people who are more dependent on media need to develop skills for being skeptical of all information sources. Giving students practice in assembling evidence for concepts they have accepted is a good review technique. Using examples from explanations of less sophisticated times has much potential. I have offered two examples here. More old concepts and explanations could be developed for science reviews. I'd be glad to hear about others that work.
©2007 by Synergy Learning International, Inc. All rights reserved.
- Jean is Professor Emerita in the Biology Department at San Jose State University in California. At SJSU she was director of the Science Education Program, and taught general education science to college students. She has concentrated on improving evolution education and education about the nature of science.