Appendix
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Simpson’s Paradox
Example of Simpson’s Paradox from The Numbers behind Numb3rs. In this example„ women are accepted at a higher rate (or roughly equal rate) to all of Berkeley’s programs, but are accepted a a lower rate when those acceptances are combined into university-wide stats. Why? Because women apply to more competitive programs… Continue reading
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A good example of age as confounder
From The Numbers behind Numb3rs: Cobb illustrated the distinction by means of a famous example from the long struggle physicians and scientists had in overcoming the powerful tobacco lobby to convince governments and the public that cigarette smoking causes lung cancer. Table 2 shows the mortality rates for three categories of people: nonsmokers, cigarette smokers,… Continue reading
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Predictive Efficiency
From Farrington & Tarling’s Prediction in Criminology, a new term: predictive efficiency. The way to think about it is this — suppose I say that a college education predicts low incidence of being convicted of a violent crime, and at the end of the day I’m right — over the course of a year, 97.5%… Continue reading
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Incidence, Prevalence, and the Obama Job Record
Since the statistics class I teach is supposed to be integrative — that is, to show connections between various disciplines and other aspects of life — I’m always on the lookout for ways to jury-rig an understanding from one domain to understand another. I think I just found a neat example. But first, look at… Continue reading
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From Swing Voters via ilovecharts This is a great example for students of how longitudinal measurement is sometimes used in polling to understand the effect of a specific event. The post-speech numbers alone tell us a bit about Obama’s popularity, but nothing about the speech. With a pre/post on the speech, we can use the post-speech gain to… Continue reading
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Diagnostic vs. Spectral Markers. From Principles of Medical Statistics. Diagnostic markers are about whether the disease is present, whereas spectral markers deal with severity and stage. Continue reading
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‘Adrift’ in Adulthood: Students Who Struggled in College Find Life Harsher After Graduation
‘Adrift’ in Adulthood: Students Who Struggled in College Find Life Harsher After Graduation From the article: Here is what they found: Graduates who scored in the bottom 20 percent on a test of critical thinking fared far more poorly on measures of employment and lifestyle when compared with those who scored in the top 20… Continue reading
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Infant mortality and choice of a base
If I have 10 kids in my class and two failed last year and one failed this year, I can say two equivalent things: 50% less students failed my course this year 10% more of my students passed. The odd thing is most students refuse when looking at such figures to believe they are equivalent… Continue reading
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Tutoring at Scale Sighting
From The Chronicle, Tenured Professor Departs Stanford U., Hoping to Teach 500,000 Students at Online Start-Up: Eventually, the 200 students taking the course in person dwindled to a group of 30. Meanwhile, the course’s popularity exploded online, drawing students from around the world. The experience taught the professor that he could craft a course with… Continue reading
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On Sex After Prostate Surgery, Confusing Data [Problems with Term Definition]
On Sex After Prostate Surgery, Confusing Data [Problems with Term Definition] A classic problem of term definition from the NYT (somewhat older article): A notable study in 2005 showed that a year after surgery, 97 percent of patients were able to achieve an erection adequate for intercourse. But last month, researchers from George Washington University… Continue reading
Hapgood 