Tag Archive for scientific method

The Scientific Method at Work

In the last article we looked at how the scientific method works, with researchers constantly checking and rechecking each other’s work. Two news stories from February 2001 illustrate how this process works.

Case 1: Doctored Data?

The medical journal Surgical Laparoscopy, Endoscopy and Percutaneous Techniques has rebuked two well-known Stanford researchers, Dr. Farr Nezhat and Dr. Camran Nezhat, and retracted two articles by the brothers. The doctors claim to have developed a new surgical technique for women with endometriosis of the rectum. Endometriosis is a condition in which uterine tissue grows outside of the uterus.

Stacey Mullen, a woman on whom the Nezhats performed the surgery, claims that the doctors destroyed her bowels and ruined her life by performing the operation on her. Mullen has sued the Nezhats in Atlanta, saying that they lied about her complications in the journal articles. Experts hired by Mullen and her attorneys examined the patient records on which the articles were based and found major discrepancies between the data in the patient records and the data reported in the articles, according to Linda Carroll and Alfred Lubrano reporting for MSNBC.

Moreover, report Carroll and Lubrano:

In June of last year, an MSNBC examination of the original Nezhat patient records revealed that the actual length of time it took to perform the surgeries was far longer than what was reported in the paper. Similarly, the amount of blood each patient lost during the procedure was significantly greater than what the Nezhats wrote. […] Even many of the patients’ ages listed in the journal article differed from those in the original records.
Experts say that the retraction of an article by the journal that published it is unusual. More often articles are retracted by their authors because further investigation has raised doubts about the validity of their research methods or analysis of data. This controversy surrounding the Nezhat brothers calls into question every other article the brothers have ever published or will try to publish in the future, the experts say.

Case 2: Flawed Theory?

Gina Kolata, well-known science writer for The New York Times, reported on February 20, 2001, that “a widespread belief about the onset of puberty in girls is coming under vigorous attack, led by a group of medical specialists who say that it is based on flawed science and that it can have dire medical consequences.”

The belief that girls are now starting puberty as early as age 6 or 7 came from a study by Dr. Marcia E. Herman-Giddens. While working as a physician’s assistant in North Carolina, Dr. Herman-Giddens, whose degree is in public health, noticed that girls as young as 7 or 8 were coming in with breasts and pubic hair.

Herman-Giddens formulated a hypothesis, and between July 1992 and September 1993, 225 pediatricians, nurses, and physicians’ assistants in private practices across the United States collected data on 17,077 girls between the ages of 3 and 12 who came into their offices. The data suggested that girls were entering puberty about a year before textbooks said was normal. In 1997 Herman-Giddens published her findings in the journal Pediatrics.

Critics say that the study’s conclusions are dangerous because “if doctors assume that girls who start developing at 6 or 7 are normal, they might miss serious medical problems like tumors or genetic disorders that can cause early puberty.” Furthermore, the critics say, a single study is not sufficient to demonstrate the hypothesis. Many of the girls in the study may have been brought in by their parents for examination because they were experiencing early puberty due to an underlying medical condition.

The Scientific Method

Every day the news is full of reports about the latest medical research. Sometimes we read about two different studies that seem to contradict each other. It’s hard to know what to believe, whose advice to follow. Before trying to decide about a particular study’s findings, it’s helpful to review what exactly is going on behind all research.

Scientists devise studies and conduct research in accordance with the scientific method. “Scientific method is what working scientists do, not what other people or even they themselves may say about it,” says physicist Percy W. Bridgman in “On Scientific Method”. Bridgman continues, “science is what scientists do, and there are as many scientific methods as there are individual scientists.” But although a scientist constructing an experiment to study something may not consciously think about pursuing the scientific method, a review of the basic facts of scientific research can help us non-scientists understand what the research and its results mean.

The scientific method has four basic steps:

Observation
Scientific investigation begins when a scientist has observed some event or characteristic of the world around us and wants to explain it. “First of all, the scientist tries to learn as much about a subject as time—or funding—allows. This requires a thorough study of the available literature, gathering information and data from a variety of sources, discussions with colleagues, and a lot of thinking” (“The Scientific Method—Elegant Experiments.” 30 Dec. 2000).

Formulation of a hypothesis
Observations lead to questions about the nature of the world, writes Anthony Carpi, Ph.D.: “In attempting to answer a question about the nature of the world, a scientist will form a hypothesis (or some would say a guess) regarding the question’s answer” (“SCI1.1-The Scientific Method.” 30 Dec. 2000). “After data has been collected and analyzed, the scientist formulates a hypothesis. It may be a short leap of logic, or an intuitive leap of faith” (“The Scientific Method—Elegant Experiments.” 30 Dec. 2000).

Prediction
The scientist then uses the hypothesis “to predict the existence of other phenomena, or to predict quantitatively the results of new observations,” says Frank Wolfs, a physics professor at the University of Rochester (“Introduction to the Scientific Method.” 30 Dec. 2000).

Experimentation
Next, the scientist develops an experiment to test the predictions. “Of all the steps in the scientific method, the one that truly separates science from other disciplines is the process of experimentation. In order to prove, or disprove, a hypothesis, a scientist will design an experiment to test the hypothesis” (Carpi).

Finally, the scientist will “[r]epeat steps 3 and 4 until there are no discrepancies between theory and experiment and/or observation. When consistency is obtained the hypothesis becomes a theory and provides a coherent set of propositions which explain a class of phenomena. A theory is then a framework within which observations are explained and predictions are made” (Jose Wudka. “What is the ‘scientific method’?” 30 Dec. 2000).