DEPARTMENT OF BIOLOGY
Why it is necessary to understand The Nature of Science
It is all too common that science is perceived as Memorizing Facts. Actually, science is an ongoing endeavor to find out new things about how the world works. There is a great difference between finding out new things, and memorizing old things. How did it get this way, what can we do about it, and why does it matter?
To find out something new, we must first determine what is already known. Although there is personal intellectual merit in re-discovering things that others have previously discovered, such re-discovery does not advance overall scientific understanding. Perhaps, for this reason, we have tended toward presenting the already-known in science classes. The logic is that this seems to be the best way to bring students up-to-speed on what is known, so that they are well prepared to advance into new areas when they are independent researchers.
Although there is merit in this logic, there are two disadvantages. First, it omits the fun part from student training. To a scientist, getting the data and thinking about it to make sense of the findings is what science is all about. It's fun. Learning what others have already discovered is seen as a necessary preliminary step, but to a practicing researcher, is not terribly exciting.
The second disadvantage to teaching science as "facts to learn" is that it encourages students adopt a thinking style that is quite different from the thinking style that is used in "doing science." For students to understand what science really is, they must practice the thought processes that scientists use. Certainly, learning what is already known is a part of it, but the fundamental investigative processes make up most of active science.
It is necessary, therefore, to incorporate scientific, investigative thinking into our classes. There are a variety of ways to do this. The most common term used to describe teaching that involves student investigation and scientific thinking is "inquiry." However, this term is rather broadly defined. Furthermore, as described by Harwood (2004), scientific inquiry does not follow any single, linear path that can be simply described (for example, using terms such as "the scientific method"). Different fields use different methods.
Although a full scientific inquiry involves defining the problem to be investigated and developing methods by which to probe that problem, I will argue that the most important aspects of a scientific approach--in terms of understanding the nature of science--are:
- obtaining data
- evaluating the data
- working from the data to propose an explanation for what happened to produce the data
- evaluating information from outside of the immediate study to be certain that the proposed explanation is not ruled out by other data
To what extent can we say that our interpretation of the data is true? How certain are we that no new data will ever be found that alters our interpretation? As a general rule, we cannot be certain. Therefore, in the strict sense, our interpretations of data are not Facts. They are simply the best interpretation that we have for the data that are currently available. It is generally not possible to "prove" a theory. All of the data we have support it, but maybe in the future, some new piece of data will be found that disproves it.
Therefore, if we teach science with the goal of providing our students with previously-discovered information, and test them on what they have memorized, we give them the impression that science is facts, and that those facts are supported by proofs. This is not what science is. Science provides merely the best interpretation of the available data. Since we don't know the answer beforehand, we can never be certain that any explanation is ever The Right Answer. The best answer is the one that has survived the most tests. This is the nature of science.
Evolution and the Nature of Science
The nature of science is especially important to understand when dealing with evolution. Students who assume that our teaching is a Listing of Facts assume that we are presenting evolution as a Fact. Some of these students look at the evidence available to them in the textbooks and in the classroom, and they see things they don't fully understand, and things that "common sense" tells them just don't seem likely. They come away with the idea that we claim to present facts, but the facts have not been proven, so evolution must be pure speculation.
When we understand the nature of science, and recognize that every theory in science is no more than the current best interpretation of the currently-available evidence, then some of the problem goes away. I say "some" because, although we may eliminate the concern that we are teaching "facts" where our students don't see proof, we make the teaching of evolution more complex (more accurate, but also more complex).
It is necessary to give our students data, and involve them in developing hypotheses to explain the data. In doing so, they may develop excellent explanations that fit current thinking in the field. It is interesting to ask them, "do you believe that what you just thought up is a Fact?" From their own uncertainty, they will begin to understand the nature of scientific theory. The theory is a good explanation, but it is still just an explanation.
It is also necessary to give our students time to explore alternative explanations. When we give them data, and they work to understand and explain the data, some groups may develop different explanations from other groups. They will ask, "which one is the right answer?" The correct reply is that we don't yet know, so we'll have to explore them. We need to develop criteria by which we can determine which explanations are better, and which fall short. Perhaps, the least traumatic way to do so is simply to bring in additional information from outside of the immediate study, and evaluate how consistent each hypothesis is with the new information. "Why don't you consider this...now get back in your groups, and think about your hypothesis again. Is your explanation still OK, or do you need to re-think it?"
After several rounds of interpreting data and developing--and changing--their explanations, students will come to understand that the data may be fact, but the interpretations are subject to change as new data come to light. Evolution is not dogma or Received Wisdom, but is an explanation of data. After several rounds of interpreting data and developing explanations, students will also know a fair amount about the nature of the data upon which evolutionary theory is based.
Students may offer other explanations of the origin of species during these data-interpretation sessions. They may have some pre-conceived, non-scientific notions on this issue. That's fine. Students should be free to interpret their data any way that they can justify. It is important to note that many of our students have not seen much actual data, so an explanation is valid for them if it fits the knowledge they currently have. It is not appropriate, and not scientific, to tell them their explanation is wrong without giving them the additional data of which they are unaware. As we bring in more and more data, and more lines of reasoning, many of these other explanations will no longer fit all of the data--and students will see why evolution is the currently-preferred theory.
Harwood, W.S. A New Model for Inquiry. Journal of College Science Teaching 33(7):29-33 (2004)