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Counting Quantitative Reasoning as a Teaching of Psychology Priority. Third International Conference on the Teaching of Psychology 13 July 2008. Neil Lutsky Carleton College, Northfield, Minnesota USA, nlutsky@carleton.edu.
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Counting Quantitative Reasoning as a Teaching of Psychology Priority Third International Conference on the Teaching of Psychology 13 July 2008 • Neil Lutsky • Carleton College, Northfield, Minnesota USA, nlutsky@carleton.edu
“One of the things that makes psychology unique is that it makes the whole scientific enterprise so clear.” Nicky Hayes, University of Bradford ICOPE 2002
“The fundamental goal of education in psychology, from which all the others follow, is to teach students to think as scientists about behavior.” Charles Brewer et al. (1993), Curriculum, Handbook for Enhancing Undergraduate Education in Psychology
The longer I have been teaching psychology, the less important I have come to believe the teaching of psychology to be!
Presentation/Argument Overview • The concepts and findings of psychology are incredibly useful in making sense of behavior in the real world. • Nonetheless, there is something else we could be emphasizing in the teaching of psychology to help students confront the world knowledgeably. • That something else reflects a central element of life and citizenship in the contemporary world: numbers. • One of the great gifts we can give students is the ability to usequantitative reasoning.
Presentation Overview (continued) • What QR habits of mind do students need to gain or strengthen? • How can we reinforce QR when teaching psychology?
The Shelf Life Problem Manning, Levine, & Collins (2007). The Kitty Genovese murder and the social psychology of helping: The parable of the 38 witnesses. American Psychologist, 62, 555-562.
“It is a proud thing to say ‘I taught him’ and a wise one not to specify what.” -Jacques Barzun
Derek Bok (2005), Our Underachieving Colleges “...certain basic quantitative methods seem applicable to a wide enough range of situations to be valuable for almost all students.”
“Learn statistics. Go abroad.”-K. Anthony Appiah, Princeton University
US: National Numeracy Network, http://serc.carleton.edu/nnn/ • Great Britain: More or Less, http://news.bbc.co.uk/2/hi/programmes/more_or_less/default.stm • International Statistical Literacy Project, http://www.stat.auckland.ac.nz/~iase/islp/home
As psychologists we believe in the power of numbers, the power of numbers to influence & the power of numbers to inform.
The Power to Inform: “Statistics can tell us things about the world that we could not imagine on the basis of our senses alone...The social world is unimaginably more complex than we can see directly from any subjective vantage point within it.” -Paul Seabright, Times Literary Supplement
“It sort of makes you stop and think, doesn’t it?”
What quantitative concepts would a reader need to know in order to make sense of this important article? • Know to Read to the end of the article! • Recognize the strengths of aRandom clinical trial vs. Case Method. • Understand Statistical Significance. • Appreciate the difference between a Single study vs. a Literature.
What do I mean by “QR” ? Quantitative reasoning is the power and habit of mind to search out quantitative information, critique it, reflect upon it, and apply it in one’s public, personal, and professional lives. -National Numeracy Network
10 QR Questions at the Ready: • What do the numbers show? • How representative is that? • Compared to what? • Is the outcome statistically significant? • What’s the effect size? • Are the results those of a single study or of a literature? • What’s the research design (correlational or experimental)? • How was the variable operationalized? • Who’s in the measurement sample? • Controlling for what other variables?
How representative is that?
Examples and stories. • “For instance is no proof.”[Old Yiddish Saying] • Extremes: • “Up to 50% off.” “Up to 36 hours...”
How might Styron’s experience not be representative of those of others suffering from depression?
“The deep, fundamental question in statistical analysis is: Compared with what?” -Edward Tufte
Is the outcome statistically significant?
Goldacre: Why do journalists so often present quantitative information poorly? “An article in a leading medical journal said...that Pargluva seemed to significantly increase heart attack and stroke risks.”
New Diabetes Drug Poses Major Risks, Panel Says Review Finds FDA Overlooked Data on Life-Threatening Cardiovascular Effects of Pargluva By Rob Stein and Marc Kaufman Washington Post Staff Writers, Friday, October 21, 2005; A02 A diabetes medicine poised to win Food and Drug Administration approval sharply increases the risk of heart problems, strokes and death, researchers reported yesterday in an analysis that raises new questions about how the agency handles drug safety concerns. New Diabetes Drug Poses Major RisksWashington Post, October 21, 2005 A new diabetes medicine...sharply increases the risk of heart problems...researchers reported yesterday. ...the analysis found those taking the drug had more than twice the risk of death, heart attacks, and strokes, and nearly triple the risk when all types of heart problems were included.
Ioannidis Review of Medical Research (Journal of the American Medical Association, 2005) Even carefully peer-reviewed studies in the medical literature may not be fully supported subsequently. Ioannidis’s research suggested that will happen about 32% of the time.
Students need to recognize: Not all research studies are experiments. Not all studies called experiments are true experiments.
RCTs: “It was more of a ‘triple-blind’ test. The patients didn’t know which ones were getting the real drug, the doctors didn’t know, and, I’m afraid, nobody knew.”
Johns Hopkins Iraqi Casualty StudyThe Lancet • Estimated 601,027 “deaths by violence”. • “For the single most important category--the total number of deaths by violence during the war--the confidence interval ranges from 426,369 to 793,663. That means that we are 95% certain that the correct number is between those two...” “If statesmen were better at arithmetic, wars would be far fewer.” -Benjamin Franklin
Medical “Efficaciousness” vs. “Effectiveness”
Controlling for what other variables?
Sir Richard Doll • British epidemiologist, who with Bradford Hill, was asked to investigate the alarming increase in lung cancer cases in Britain after WWII. • Interviewed lung cancer patients in 1949 and found that cigarettesmoking was the strongest characteristic they shared. • Went on to study 40,000 British doctors over 50 years. Found that cigarette smoking reduced the life span by an average of 10 years.
“It is easy to lie with statistics, but easier to lie without them.”-Frederick Mosteller
What can we as teachers of psychology do to promote QR habits of mind? • Teach QR skills & values. • Teach for generalization!
“Statistics and psychology have long enjoyed an unusually close relationship--for they are inextricably bound together.”-Stephen Stigler (1999)
“Science is not a collection of facts, any more than opera is a collection of notes. It’s a process, a way of thinking, a method, based on a single insight--that the degree to which an idea seems true has nothing to do with whether it is true, and that the way to distinguish factual ideas from false ones is to test them by experiment.”-Timothy Ferris (1998)
How we present information. • What we ask students to do. • What we can do as teachers.
How we present information: • Be explicit about: • Whether a study represents itself or a literature. • The contexts or typicality of examples. • How terms and concepts in psychology are related to equivalents in public discourse.
How we present information: • Preach: • Why we use numbers. • Why precision is important. • How we evaluate numbers. • How we can construct meaningful, principled, and effective arguments with numbers.
“the purpose of statistics is to organize a useful argument from quantitative evidence using a form of principled rhetoric.”-Robert Abelson
Use findings from psychology to underscore the virtues of Q inquiry. • Cognitive heuristics: Lawson et al. (2003), Teaching of Psychology. • Misperceptions of chance: http://thehothand.blogspot.com/ • The psychology of belief.