Presentation on theme: "Testimonials Plausibility. Research is probabilistic."— Presentation transcript:
Research is probabilistic
Research reveals tendencies
Single cases can be found in support of any belief
Single cases can be found to refute any claim
How much data before the tendency is revealed?
Testimonials – even large numbers of people can be wrong
Homeopathy History – from humours to dynamic system Today – 100K physicians, 500M patients Drugs – 3K drugs, including Rabies! Machines: James Randi video -
Self-Deception How can an honest person mistake worthless treatment for one that works? We are going to talk about 10 Competing Explanations
10 Competing Explanations The Placebo Effect The simple expectation of recovery sometimes has a positive effect
10 Competing Explanations Spontaneous Remission Sometimes diseases disappear without any treatment
10 Competing Explanations The Disease Ran its Natural Course If a disease is not chronic or fatal, it may be self- limiting
10 Competing Explanations The Cyclical Nature of Many Diseases Even chronic conditions go through phases
10 Competing Explanations Misdiagnosis There may be no disease in first place
10 Competing Explanations The Worried Well Some people with no disease nonetheless seek health care
10 Competing Explanations Symptomatic Relief Alleviation of symptoms does not necessarily mean the disease has been cured
10 Competing Explanations Hedged Bets People sometimes simultaneously receive evidenced-based health care
10 Competing Explanations Derivative Benefits Purely psychological benefits can lead to people taking better care of themselves
10 Competing Explanations Psychological Distortions of Reality Cognitive dissonance can distort perceptions of the effectiveness of treatment
Cognitive Dissonance Cognitive dissonance is a psychological term which describes the uncomfortable tension that comes from holding two conflicting thoughts at the same time. To reduce the dissonance, people modify one of the two thoughts, or invent new thoughts
UFOs Some respectable people believe in UFOs Its world-wide Some sightings defy explanation Some sightings appear like hoaxes Some sightings are pretty cool!
Alien Abductions Alternative explanations Contamination Effect Sleep paralysis NOVA Kidnapped by UFOs?