[RUME] Statistical Illiteracy

[Richard Hake]

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ABSTRACT: I copy most of the summary of the article "Helping Doctors 
and Patients Make Sense of Health Statistics" by Gigerenzer et al., 
who claim that statistical illiteracy is common to patients, 
journalists, and physicians; and emphasize the "importance of 
teaching statistical thinking and transparent representations in 
primary and secondary education as well as in medical school [since] 
statistical literacy is a necessary precondition for an educated 
citizenship in a technological democracy."
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Some subscribers may be interested in a recent article by Gigerenzer 
et al. (2008) titled "Helping Doctors and Patients Make Sense of 
Health Statistics."

The summary reads [bracketed by "GGGGGG. . . ."; my EMPHASIS]:

GGGGGGGGGGGGGGGGGGGGGGGGGGGGG
Many doctors, patients, journalists, and politicians alike do not 
understand what health statistics mean or draw wrong conclusions 
without noticing. Collective statistical illiteracy refers to the 
widespread inability to understand the meaning of numbers. For 
instance, many citizens are unaware that higher survival rates with 
cancer screening do not imply longer life, or that the statement that 
mammography screening reduces the risk of dying from breast cancer by 
25% in fact means that 1 less woman out of 1,000 will die of the 
disease. We provide evidence that STATISTICAL ILLITERACY (a) IS 
COMMON TO PATIENTS, JOURNALISTS, AND PHYSICIANS; (b) is created by 
nontransparent framing of information that is sometimes an 
unintentional result of lack of understanding but can also be a 
result of intentional efforts to manipulate or persuade people; and 
(c) can have serious consequences for health. . . . . . . .We show 
that information pamphlets, Web sites, leaflets distributed to 
doctors by the pharmaceutical industry, and even medical journals 
often report evidence in nontransparent forms that suggest big 
benefits of featured interventions and small harms . . . .[see e.g., 
Smith (2005)]. . . .  Without understanding the numbers involved, the 
public is susceptible to political and commercial manipulation of 
their anxieties and hopes, which undermines the goals of informed 
consent and shared decision making.

What can be done? WE DISCUSS THE IMPORTANCE OF TEACHING STATISTICAL 
THINKING AND TRANSPARENT REPRESENTATIONS IN PRIMARY AND SECONDARY 
EDUCATION AS WELL AS IN MEDICAL SCHOOL. Yet this requires 
familiarizing children early on with the concept of probability and 
teaching statistical literacy as the art of solving real-world 
problems rather than applying formulas to toy problems about coins 
and dice. A major precondition for statistical literacy is 
transparent risk communication. We recommend using frequency 
statements instead of single-event probabilities, absolute risks 
instead of relative risks, mortality rates instead of survival rates, 
and natural frequencies instead of conditional probabilities. 
Psychological research on transparent visual and numerical forms of 
risk communication, as well as training of physicians in their use, 
is called for.

Statistical literacy is a necessary precondition for an educated 
citizenship in a technological democracy. Understanding risks and 
asking critical questions can also shape the emotional climate in a 
society so that hopes and anxieties are no longer as easily 
manipulated from outside and citizens can develop a better-informed 
and more relaxed attitude toward their health.
GGGGGGGGGGGGGGGGGGGGGGGGGGGGG

Gigerenzer <http://tinyurl.com/5q7wf> is Director of the Max Planck 
Institute for Human Development <http://www.mpib-berlin.mpg.de/> in 
Berlin. For Amazon.com's list of his books see 
<http://tinyurl.com/6ngte3>.

  I thank psychologist Chris Green (2008) for his TIPS [Teaching in 
the Psychological Sciences 
<http://www.mail-archive.com/tips%40acsun.frostburg.edu/>] post that 
brought Gigerenzer et al. (2008) and Smith (2005) to my attention.

Richard Hake, Emeritus Professor of Physics, Indiana University
24245 Hatteras Street, Woodland Hills, CA 91367
<rrhake at earthlink.net>
<http://www.physics.indiana.edu/~hake/>
<http://www.physics.indiana.edu/~sdi/>
<http://HakesEdStuff.blogspot.com/>

REFERENCES
Gigerenzer, G., W. Gaissmaier, E. Kurz-Milcke, L.M. Schwartz, & S. 
2008. "Helping Doctors and Patients Make Sense of Health Statistics," 
Psychological Science In The Public Interest 8(2): 53-96; online at 
<http://www.psychologicalscience.org/journals/pspi/pspi_8_2_article.pdf> 
(1.8MB).

Green, C. 2008." Why do we have journals again?" TIPS post of 24 Oct 
2008 08:19:19-0700; online at 
<http://www.mail-archive.com/tips@acsun.frostburg.edu/msg26734.htm>.

Smith, R. 2005. "Medical journals are an extension of the marketing 
arm of pharmaceutical companies," PLoS Medicine 2(5); online at 
<http://www.aliveandwell.org/docs/richard_smith_medical_journals.pdf> 
(388 kB).