11.1 Pathological Science
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How to catch bad science.
The Lesson in Context
This lesson teaches students to be cautious of bad science of all kinds and aware of the signs thereof. We ask students to study a few established examples of pathological science in history dressed as science merely in form. The emphasis is on well-intentioned researchers "falling in love" with their own ideas, finding excuses to justify them even when reality has turned out to be contrary to them.
Although blatant pseudoscience such as flat earth, astrology, creationism, and alternative medicine are also included, what deserves particular attention is seemingly genuine science done by seemingly genuine people that is nevertheless incorrect, possibly due to the researchers' own hubris.
- Everyone in principle has access to the same shared reality. If a certain (amazing) result by one research group cannot seem to be replicated by many other groups, it is a good sign that it does not accurately describe the shared reality.
- Overstating the confidence level of a scientific result is a sign of bad science.
- It is expected that patterns arise from random noise. Good science can also turn out to be wrong just by chance, but stubbornly sticking with the original result would turn it into bad science.
- In the spirit of personal persistence and iterative progress, setbacks such as a wrong or disappointing result should be accepted as an inevitable part of this progress.
- Though not yet widely employed in all fields of science, various blind analysis techniques can help reduce the possibility that a scientific result may be contaminated by subtle analysis choices made by the researchers that are (often subconsciously) motivated by the desire for a certain anticipated result.
- Bad science is particularly problematic when it concerns the study of human subgroups, as it may be motivated by or may perpetuate preexisting inequitable power structures in society.
Takeaways
After this lesson, students should
- Be able to distinguish roughly among the following:
- Good science that gets the wrong answer.
- Fraudulent science.
- Pathological science.
- Poorly-done science.
- Pseudo-science.
- Feel comfortable using Langmuir's Pathological Science Indicators to assess scientific articles.
- Be able to identify what is wrong in cases of fraudulent, pathological, poorly-done, and pseudo-science.
Spectrum of Poor Research
- Good Science
- Poorly-done Science
- Pathological Science
- Pseudo-science
- Fraudulent Science
Langmuir's Pathological Science Indicators
- The effect is produced by a barely detectable cause, and the magnitude of the effect is substantially independent of the intensity of the cause.
- The effect is barely detectable, or has very low statistical significance.
- Claims of great accuracy.
- Involving fantastic theories contrary to experience.
- Criticisms are met with ad hoc excuses.
- Ratio of supporters to critics rises to near 1:1, then drops back to near zero.
There is no set number of Langmuir's criteria that determines whether something is pathological science or not. The criteria serve as a useful guide, but detecting pathological science is ultimately something of an art. That being said, whether or not a given study is a case of pathological science depends on the attitude of the researchers. Indicators 3 and 5 speak to this most directly.
This paper's result could not be replicated by others in the field, therefore the authors have committed pathological science.
Useful Resources
Recommended Outline
Before Class
Each student will have read one of the three articles that we discuss in this section, as well as an article by Langmuir. Assign each group to one of the three articles one week ahead of time, and then send another reminder to read them one or two days before the lesson. Also make sure to print the handout.
During Class
| 5 Minutes | Introduce the lesson and go over the plan for the day. Make sure people have groups, spokespeople, etc. |
| 15 Minutes | Review the definitions for this lesson. |
| 60 Minutes | Run the poor science case studies activity. |
Lesson Content
Poor Science Case Studies
Students are assigned one of three scientific articles to skim through before class and asked to assess the validity of its methodology, with reference to Langmuir's indicators for pathological science. They may follow the handout.
Instructions
| 15 Minutes | Students review their articles in small groups and answer the questions in the handout. A note taker should be responsible for writing down ideas from the group. |
| 20 Minutes | Since each group has been assigned one of three articles, we now bring three groups with different articles together. Each group's spokesperson will spend 3-5 min presenting their group's article to the other groups using their answers to the small-group questions on the handout as a guide. |
| 25 Minutes | Call the whole class together and go over the final discussion questions. Try to come up with a class consensus for each article. |
Small-group Questions
These are the questions on the handout that small groups will use to guide their discussion. Only after taking notes that answer these will they go over the final discussion questions. These questions are the same for each group no matter what article they were assigned.
- What was the research question and hypothesis?
- What variables were tested?
- Do you have a sense that there were other confounding factors that were controlled for?
- How did the scientific community respond? How did the scientists who conducted the research respond to the scientific community?
- What did the scientists conclude? What did the scientific community conclude?
Final Discussion Questions
These questions are used for each article. They are initially discussed in small groups and then answered collectively by the entire class. The third question is intended mainly for small groups so as to serve as fodder for the larger discussion.
- Where does this article fall on the poor science scale?
- Which of Langmuir's criteria (if any) apply to this article?
- Where, if anywhere, did this science go wrong?
Study A: Arsenic Bacteria
Summary
This paper discussed a novel substitution of arsenic for phosphorus in bacterial DNA, which would have profound implications on requirements for life in any form. They reported the discovery of an unusual microbe that could vary elemental composition of its basic biomolecules by substituting arsenic for phosphorus. Mechanisms for such substitution were unknown. Many criticisms were published as technical comments in Science and online, such as accusing the original team of failing to "meticulously clean up the DNA first". An Israeli team worked out the mechanism by which the bacterium in question discriminated between nearly identical molecules of phosphate and arsenate. Science also published an official statement saying some of the findings in the original paper were incorrect in 2012.
Answers
- Where does this article fall on the poor science scale?
Poorly-done science. Wrong results.
- Which of Langmuir's criteria (if any) apply to this article?
- The effect is produced by a barely detectable cause, and the magnitude of the effect is substantially independent of the intensity of the cause.
- The effect is barely detectable, or has very low statistical significance.
- Claims of great accuracy.
- Involving fantastic theories contrary to experience.
- Criticisms are met with ad hoc excuses.
- Ratio of supporters to critics rises to near 1:1, then drops back to near zero.
- Where, if anywhere, did this science go wrong?
The experiment was not done carefully enough.
Study B: Water Memory
Summary
This paper provided evidence for the theory that water retains memory of previously dissolved substances, which has been claimed to be a mechanism by which homeopathic remedies work, but runs contradictory to our current understanding of chemistry and physics. However, since the paper had no apparent methodological problems, it was published in Nature accompanied with an editorial that noted "There are good and particular reasons why prudent people should, for the time being, suspend judgment" and described some of the fundamental laws of chemistry and physics which it would violate, if shown to be true. Additionally, the editor of Nature demanded that the experiments be re-run under supervision. In the supervised double-blind experiments, no memory effect was observed. Nature published a follow-up report of these findings, and their editor said: "We believe the laboratory has fostered and then cherished a delusion about the interpretation of its data." and pointed out that two of the researchers were being paid for by a homeopathic company. The PI also published a follow-up letter where he compared his treatment by the Nature team to "Salem witchhunts or McCarthy-like prosecutions". More drama ensued, and the results of the paper are still used to claim that the experiments "prove" that homeopathy works.
Answers
- Where does this article fall on the poor science scale?
Pathological science.
- Which of Langmuir's criteria (if any) apply to this article?
- The effect is produced by a barely detectable cause, and the magnitude of the effect is substantially independent of the intensity of the cause.
- The effect is barely detectable, or has very low statistical significance.
- Claims of great accuracy.
- Involving fantastic theories contrary to experience.
- Criticisms are met with ad hoc excuses.
- Ratio of supporters to critics rises to near 1:1, then drops back to near zero.
- Where, if anywhere, did this science go wrong?
The researchers were very attached to their scientific findings and criticized the supervised experiments.
Study C: Superluminal Neutrinos
Summary
Neutrinos are subatomic particles with extremely small masses, which means that they should move at very nearly (but slightly slower than) the speed of light. In this paper, neutrinos created at CERN were detected at another site in Italy to measure the precise arrival time and distance, and therefore the speed at which neutrinos travel. They found that neutrinos traveled slightly faster than the speed of light with high significance (over 15,000 separate neutrino events). If this is correct, it would overturn a cornerstone of modern physics. The team published their preliminary data to the public to enlist the help of other scientists for searching for an explanation, and doubled down on their efforts to find an explanation for this result. The team's in-depth investigation of their experiment turned up a few errors, which when corrected found that the speed was consistent with the speed of light. Other independent experiments also found that neutrinos traveled at the speed of light, but showed no evidence for faster than the speed of light.
Answers
- Where does this article fall on the poor science scale?
Good scientific practice. Wrong results.
- Which of Langmuir's criteria (if any) apply to this article?
- The effect is produced by a barely detectable cause, and the magnitude of the effect is substantially independent of the intensity of the cause.
- The effect is barely detectable, or has very low statistical significance.
- Claims of great accuracy.
- Involving fantastic theories contrary to experience.
- Criticisms are met with ad hoc excuses.
- Ratio of supporters to critics rises to near 1:1, then drops back to near zero.
- Where, if anywhere, did this science go wrong?
Even very carefully done science may inevitably contain errors. The team recognized the implications of the results and openly invited other scientists to critique their procedure, leading to the discovery and correction of the relevant errors.
This example illustrates that a couple of Langmuir's criteria in-and-of themselves do not mean that a certain study is a case of pathological science. If the researchers fully acknowledge the implications and limitations of their results and do everything in their power to prove themselves wrong then it is likely still an example of good scientific practice.