Archive for the ‘Uncategorized’ Category.

Confidence Intervals for Medians and Percentiles

Medians are better than means in most interpretation contexts: they’re not affected by skewed or otherwise non-normal distributions. They give a better sense of the “typical” data point. When the mean and median differ, I prefer to use the median.

One problem with using medians is that you can’t calculate a confidence interval for them the same way as you calculate one for a mean. There’s no “standard error of the median”. However, it turns out there is a way to calculate confidence intervals for them. Continue reading ‘Confidence Intervals for Medians and Percentiles’ »

Review of “Building Data Science Teams” by DJ Patil

Having recently committed myself to earning my living as a Data Scientist, I’ve been reading anything I can find to guide my self-education. So I just spent the last hour reading and mulling over DJ Patil‘s article/report Building Data Science Teams (BDST henceforth) which is available free from various outlets; I read the Kindle version.  (Disclaimer: DJ is a friend and occasional drinking buddy.) Continue reading ‘Review of “Building Data Science Teams” by DJ Patil’ »

Planned Serendipity

Yesterday I got back from a great APSA in Seattle.  My undergraduate students were despondent at me having to cancel class Thursday so I could attend.  A few were curious about what happens at a scientific conference and asked about the structure.  I explained that there would be several thousand political scientists at this conference and that most of the planned interaction would take place in panels. Continue reading ‘Planned Serendipity’ »

We all carry the scars

I served in the US Navy for a few months in 1986, five years in the early 90s, and another year and a half in the reserves. I was never asked to shoot someone. I never pulled a trigger when the weapon was aimed at a person. I served during, but not “in” the first Gulf War. I served during “peacetime”, or at least that’s how I thought about it. However, over the last few months I have been thinking more about my time in uniform, realizing the lasting and deep effects that experience had on me. Continue reading ‘We all carry the scars’ »

Change of Intuition about the Definition of Insanity

My dad and I went to the recent Brown/Whitman California gubernatorial debate here at UC Davis. It was fun seeing “democracy” live and up close. One of the candidates twice repeated an old saw:

One definition of insanity is doing the same thing over and over and expecting different results.

Continue reading ‘Change of Intuition about the Definition of Insanity’ »

Dimensionality matters: three implications of ideology being multidimensional

Left or right? Liberal or conservative? Blue or red?  We know the terms bandied about in the punditverse, but it’s easy to forget that there is more than one way to divide the world into two political ideologies.

Continue reading ‘Dimensionality matters: three implications of ideology being multidimensional’ »

The better the question, the worse the answer

Justin Wolfers wrote recently about the level of interaction between economics and other social sciences.  In particular, he wonders why economic work is not well represented in a list of the books most cited in social science research.  It’s a good question: I find many of the tools and techniques developed by economists are useful in my works studying political phenomena, and I do cite economic research.

One particularly thoughtful commenter on Wolfers’ post notes that economics combines the controversy of addressing everyday issues with the general inaccessibility of chemistry.  This conflict may make some people resist the conclusions of economists, ie. strong prior + incomprehensible evidence = small amount of updating.

Continue reading ‘The better the question, the worse the answer’ »

You’re Asking the Wrong Question, Fortunately

Today I got up, finishing a decision I started last night about how much to sleep before today.  I will choose my attire to fit the weather and strike the right tone in the classes I will teach. I will go to work and spend the day at work making optimal decisions about how to allocate my time and effort considering my immediate goals, teaching effectively and  preparing for an experiment, and longer term goals like getting along with my peers and building my tenure packet.  I will come home along a route that balances safety, convenience, fuel economy, and curiosity.  I will talk with my wife, play with my daughter, read to my son, all with an eye toward building both their individual lives and my relationships with them.  I may make a few allocation decisions about improving our house or saving for retirement.  I will decide whether to work out tomorrow morning, then  begin the decision about how much to sleep before tomorrow.

Continue reading ‘You’re Asking the Wrong Question, Fortunately’ »

All Theorists are Normative (or run that risk)

A recent exchange at the excellent Cheap Talk focused on how the uselessness of the United States’ recent promise not to nuke other states who comply with the Nuclear Non-Proliferation Treaty (NPT).

Continue reading ‘All Theorists are Normative (or run that risk)’ »

Terrorism is not Lightning or Peanut Butter

I came across the book Panicology, where “Two Statisticians Explain What’s Worth Worrying About (and What’s Not) in the 21st Century”.  The back cover chastens the reader:


More Americans have been killed by lightning or by peanut allergies than by terrorist attacks.

I’ve read this comparison in different forms many times; it is true, but misleading.

Continue reading ‘Terrorism is not Lightning or Peanut Butter’ »