Welcome to the Nexus of Ethics, Psychology, Morality, Philosophy and Health Care

Welcome to the nexus of ethics, psychology, morality, technology, health care, and philosophy
Showing posts with label False Positive. Show all posts
Showing posts with label False Positive. Show all posts

Wednesday, June 10, 2015

I Fooled Millions Into Thinking Chocolate Helps Weight Loss. Here's How.

By John Bohannon
i09
Originally published May 27, 2015

Here is an excerpt:

Here’s a dirty little science secret: If you measure a large number of things about a small number of people, you are almost guaranteed to get a “statistically significant” result. Our study included 18 different measurements—weight, cholesterol, sodium, blood protein levels, sleep quality, well-being, etc.—from 15 people. (One subject was dropped.) That study design is a recipe for false positives.

Think of the measurements as lottery tickets. Each one has a small chance of paying off in the form of a “significant” result that we can spin a story around and sell to the media. The more tickets you buy, the more likely you are to win. We didn’t know exactly what would pan out—the headline could have been that chocolate improves sleep or lowers blood pressure—but we knew our chances of getting at least one “statistically significant” result were pretty good.

Whenever you hear that phrase, it means that some result has a small p value. The letter p seems to have totemic power, but it’s just a way to gauge the signal-to-noise ratio in the data. The conventional cutoff for being “significant” is 0.05, which means that there is just a 5 percent chance that your result is a random fluctuation. The more lottery tickets, the better your chances of getting a false positive. So how many tickets do you need to buy?

The whole article on the scam research that fooled millions is here.

Wednesday, April 16, 2014

Statistical Flaw Punctuates Brain Research in Elite Journals

By Gary Stix
Scientific American
Originally published March 27, 2014

Here is an excerpt:

That is the message of a new analysis in Nature Neuroscience that shows that more than half of 314 articles on neuroscience in elite journals   during an 18-month period failed to take adequate measures to ensure that statistically significant study results were not, in fact, erroneous. Consequently, at  least some of the results from papers in journals like Nature, Science, Nature Neuroscience and Cell were likely to be false positives, even after going through the arduous peer-review gauntlet.

The entire article is here.

Sunday, December 1, 2013

The Crisis in Social Psychology: Paul Bloom on Bloggingheads.tv

Paul Bloom interviews Joseph Simmons about the crisis in social psychology.  They discuss the experimental method, the ability to replicate studies, false positives, and studies with "sexy findings".



The entire web site is here.

Tuesday, May 21, 2013

DSM-IV Boss Presses Attack on New Revision

By John Gever, Deputy Managing Editor
MedPage Today
Published: May 17, 2013

A new edition of psychiatry's diagnostic guide "will probably lead to substantial false-positive rates and unnecessary treatment," charged the man who led development of the last version.

To be released this weekend at the American Psychiatric Association's annual meeting, the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, or DSM-5, "introduce[s] several high-prevalence diagnoses at the fuzzy boundary with normality," according to Allen Frances, MD, who chaired the task force responsible for DSM-IV issued in 1994.

Frances, now an emeritus professor at Duke University, wrote online in Annals of Internal Medicine that changes from DSM-IV will apply disease labels to individuals who may be unhappy or offensive but still normal. Such individuals would include those experiencing "the forgetfulness of old age" as well as children with severe, chronic temper tantrums and individuals with physical symptoms with no medical explanation.

He also worried about new marketing pushes from the pharmaceutical industry seeking to exploit what he believes are "loose" diagnostic criteria in the new edition. "Drug companies take marketing advantage of the loose DSM definitions by promoting the misleading idea that everyday life problems are actually undiagnosed psychiatric illness caused by a chemical imbalance and requiring a solution in pill form," he wrote.

The entire article is here.