January 2012
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Ecological Validity
Term of the day: ecological validity. Ecological validity is a pretty big concern in ed psych, obviously. But I’ve also just read an interesting paper in Health, Risk, and Vulnerability which talks about the ecological validity of psychiatric assessment of criminals being treated for mental illness. The idea there is that many prisoners that do poorly in Continue reading
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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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