What is the scientific method?

Overview

The phrase “scientific method” is used in two contexts; the first is a formal method for determining truth. It involves the elements of laws, hypotheses, experiments, and theories. The second context of scientific method is how scientists actually work, and it seldom involves the first context.

Formal scientific method is no longer taught to aspiring scientists. Indeed, one survey of first-year college chemistry and physics textbooks showed no mention of the term. For many therapies and techniques in complementary and alternative medicine, the formal science is absent or less than adequate.

Formal Scientific Method

A law, in formal scientific method, is something all persons believe to be true but which cannot be proven. The law of conservation of mass (that mass is neither created nor destroyed, but only transformed) was believed for more than a century, until nuclear reactions converted mass into energy. This law was then modified into the law of conservation of mass and energy (that the sum of mass and energy in the universe is a constant). One of the hallmarks of science is a willingness to change any aspect of a belief when enough evidence is available to a reasonable person that such change is appropriate; there are no absolutes in science.

A hypothesis is a verifiable statement about truth. An experiment is a test of whether a hypothesis is true, and a theory is a condensation of all the experiments that support the truthfulness of a hypothesis. A theory always has some reproducible, well-designed experiment in support of it, and some theories have hundreds of thousands of observations supporting them. This all sounds grand and ideal, but neither the formal scientific method nor any of the several other scientific methods proposed by philosophers of science are how science is actually done.

Modern science has amassed a virtually infinite body of knowledge. The chance that any scientist is really working on something new is small. In reality, for example, a young scientist joins a laboratory (such as a group studying the genetics of cholesterol metabolism) and is assigned a small bit of the laboratory’s efforts (such as finding and isolating the gene that has changed in one patient’s deviated cholesterol metabolism). There is no need for hypotheses, and the theory of genetics is already abundantly supported. What this young scientist is taught in exquisite detail, especially at higher levels of education, is appropriate experimental design.

A particular mistake often made in medicine and biology can be illustrated as follows: An experimenter mashes up the leaves of the herb in ethyl alcohol and filters the extract. He or she then applies the extract to a patient’s rash; within two days the rash has been cured. This outcome sounds plausible: Something in the herb cured the rash.

Consider, however, this statement: A person’s alarm clock goes off, and then the sun comes up. Even if the person observes this several days in a row, no cause-and-effect relationship exists between the alarm clock making a noise and the occurrence of dawn. One event followed by another event does not mean that the second event was caused by the first event. In the earlier example, it is not known if the ethyl alcohol cured the rash or if the rash would have cured itself in two days without intervention.

These types of errors can be subtle. For example, a study to find out if a certain drug had a curative effect on bedsores in hospitalized persons can be clouded by the fact that one-third of the persons with bedsores will be cured simply by signing up for the research and receiving no treatment whatsoever. Bedsores are caused by a lower standard of care and when persons cannot move around in bed.

Double-Blind Clinical Study

The only acceptable experiment is the double-blind clinical study. In this type of study, the participant population must be large, and treatment and controls must be masked (blinded) so that neither the physician nor the participant knows who is receiving treatment versus control. These studies are the standard for acceptability to physicians and scientists, the final frail line that stands between science and pseudoscience.

Bibliography

Iyioha, Ireh. “Law’s Dilemma: Validating Complementary and Alternative Medicine and the Clash of Evidential Paradigms.” Evidence-Based Complementary and Alternative Medicine, September 21, 2011. Available at http://www.ncbi.nlm.nih.gov/pmc/articles/pmc2952302.

Kantor, M. “The Role of Rigorous Scientific Evaluation in the Use and Practice of Complementary and Alternative Medicine.” Journal of the American College of Radiology 6, no. 4 (2009): 254-262.

Neutens, James J., and Laurna Rubinson. Research Techniques for the Health Sciences. 4th ed. San Francisco: Benjamin Cummings, 2010.

Wilson, E. Bright. An Introduction to Scientific Research. 1952. New ed. New York: Dover, 1990.