Some thoughts on the scientific method
What do we mean by the scientific method?
There is no standard definition of the scientific method. One could say that it begins with empirical data, remains controlled by it, and then uses critical reasoning to draw conclusions, all the while trying to verify and falsify each step of the process. Alternatively, one might say that the scientific method is sound thinking applied to solid data, with results being continually tested and conclusions remaining provisional. Whatever its definition, the scientific method is marked by a strict adherence to observation, objectivity, rationality, testing, and revising.
Another way to understand the scientific method is to list its characteristics. First and foremost, it is empirical, that is, it is based on observations of the world as it is rather than on speculations about what it might be. In order to minimize errors in these observations, the scientific method is objective, that is, it relies on standardized, reproducible techniques for generating the observations, testing them, and attempting to reproduce them in other laboratories. It is rational as it employs logical thinking and critical reasoning to minimize errors of interpreting the data. Although it is not widely recognized, the scientific method is largely one of trial and error, the most common method used by the practitioner to select explanations (hypotheses) to be tested and refined. Once a hypothesis has been selected, it is tested. It can be verified or, more importantly, falsified. All scientific hypotheses must be falsifiable; any idea or explanation that cannot be falsified is unscientific and therefore basically useless—it should be discarded immediately. By means of such attempted falsification, the scientific method is ultimately self-correcting. Of course, any hypothesis that is falsifiable is also vulnerable. If you are to be a scientist, you must be willing to have your ideas tested rigorously.
Even after a hypothesis has survived one or more tests, it is still not proven; it is merely retained. It is provisional only. In the words of Sir Karl Popper, scientific knowledge (and indeed all knowledge) is conjectural. (Some people prefer provisional, which means the same thing but sounds softer.) Just as all stars ultimately die, all scientific hypotheses, including our pet creations, are ultimately falsified and discarded. Depressing but true. (Science is a tough business—not for the faint of heart.) Thus the scientific method proves nothing and eventually disproves everything.
Science and the scientific method are not intuitive, natural, or easy. A recent book by Lewis Wolpert explains to nonscientists why science is so easy to misunderstand: Science seems unnatural because it deals with entirely different realms of nature than the tiny corner of the universe on earth that our brains have been optimized to deal with. So if you are having a hard time understanding scientific ideas or thinking "scientifically," don’t worry. It’s just the way we are built.
It also turns out that there is no single, rigid scientific method that guarantees you to succeed, no "scientific cookbook" with a fixed series of steps to follow. Different branches of science operate in quite different ways. About all they hold in common is depending on objective observations, generating hypotheses by trial and error (polite terminology for guessing, and sometimes wildly), reasoning rigorously, checking data and ideas fiercely, and continually searching for newer and better explanations for old observations.
Contrary to what most of have been taught, the scientific method is often biased. For example, the choice of topics to study is commonly constrained by the values of a society as expressed through priorities of its funding agencies. Also, the nature of hypotheses posed by investigators often reflects their individual backgrounds. But biases like this are not always bad. They may even be desirable, as in the case of formulating hypotheses, where one person’s bias may be another’s creativity. The wider the range of hypotheses available to challenge established ideas, the better. But bias affects on the intermediate steps of science—thanks to the self-correcting nature of science and the uniqueness of the real world, the final results of the scientific process are independent of the path used to derive them.
Borrowing from the cultural anthropologist Robin Fox, we can say that the scientific method often produces trivial results—dull experiments and resulting data that represent only incremental advances over present knowledge. But that is the price we must pay for a few large advances. If waste, duplication, and incrementalism are required in order to produce a few great experiments, then we are certainly better off with the waste than without any science.
Is the scientific method perfect?
No. It is wrong more often than right. It can be abused by evil people (the Nazis experimenting on people, for example). It is wasteful each time that it is wrong. It can be and is imprinted with cultural bias. But it is the best system mankind has yet devised to learning about the regularities in our universe. It works where other systems fail. In the last few hundred years, its successes have been stunning.
Why is the scientific method so important?
The scientific method is important because it is by far the most successful way of understanding the world and dealing with it that has ever been devised. Every educated person needs to be familiar with its principles and practices.
Broader than science
The scientific method is not something foreign to all of us, something that might as well have come from another plant. Rather, it is an extension and refinement of how we operate in our daily lives. Every day we assemble data (observe the world), guess at what they mean (formulate hypotheses), and retain some of the guesses and eliminate others (confirm and falsify hypotheses). The difference is that we don’t do these things as carefully, systematically, and rigorously as scientists do.
Professionals in other disciplines also use something akin to the scientific method in their work. Read a good history book and see how the writer sifts through huge masses of historical data in search of the true explanations for events big and small. Revisit your favorite detective story and evaluate how the investigator reasons his way ever closer to the final answer. In many detective novels, the hero even creates new experiments to confirm his big hypothesis, as in the final, climactic scenes of a Perry Mason or a Hercule Poirot novel. Or, as Fox says, "The real poet, like any artist, tries all the time to see the general in the particular. In this he is no different from the scientist." Thus the main tenets of the scientific method are shared by all areas of critical thinking.
On the other hand, there remains something distinctive about the scientific method as practiced by scientists. As Susan Haack as written, "What is distinctive about inquiry in the sciences is, rather: systematic commitment to criticism and testing, and to isolating one variable at a time; experimental contrivance of every kind; instruments of observation from the microscope to the questionnaire; sophisticated techniques of mathematical and statistical modeling,; and the engagement, cooperative and competitive, of many persons, within and across generations, in the enterprise of scientific inquiry."
Will we be using the scientific method in PSC482G?
Strictly speaking, we will not, because the assassination of John F. Kennedy was not an experiment that we can study by replicating it. We can use most of the rest of the scientific method, though. We can check the available evidence and discard any pieces that are false or unfalsifiable. We can check the current crop of "theories" and trash all that are not falsifiable. We can aggressively take the remaining solid evidence, create a series of explanations from it, discard any that don’t measure up, and keep as a starting point the simplest explanation that remains. We can then test this one, discard it if necessary, and keep going until we have a solid working hypothesis, which we will be sure to remember is only provisional. Then we can get an "A" on our final exam and go on to the next chapter in our lives, secure in the understanding that we have done the best possible job on the assassination.
When we have done all this, we will have approached what Susan Haack calls the "genuine inquirer": "The genuine inquirer, by contrast, wants to get to the truth of the matter that concerns him, whether or not that truth comports with what he believed at the outset of the investigation, and whether or not his acknowledgment of that truth is likely to get him tenure, or make him rich, famous, or popular. He is motivated, therefore, to seek out and assess the worth of evidence and arguments thoroughly and impartially; to acknowledge, to himself as well as to others, where his evidence and arguments seem shakiest and his articulation of the problem vaguest; to go with the evidence even to unpopular conclusions or conclusions that undermine his formerly deeply held convictions; and to welcome someone else’s having found the truth he was seeking."
A recommended pattern of critical thinking
So how, practically speaking, can we reach these lofty goals in PSC482G? Here is a series of steps that I recommend highly for our critical inquiry. It is not fully original. (What is?) It can be used just about anywhere. It might be called the scientific method for the rest of us.
By the end of PSC482G, you will know this method inside out.