Yesterday I added a blog to the ReproducibleResearch.org web site. You can visit the site here or subscribe via RSS. I’d like a couple people to join me in writing this blog, and I would greatly appreciate suggestions, guest posts, etc. If you’re interested, please send a note to contribute at the domain name.

Thomas Guest posted a great article today called Distorted Software that, among other things, points out the problem with software diagrams with big boxes and little arrows: Most of the work will go into making the connections work.  In other words, the bulk of the work is in the little arrows, not the big boxes. He suggests a better diagram might look like [...]

When I was in college, my saxophone teacher recommended I study Michael Brecker. I enjoyed his music, especially his recordings with Steps Ahead, but for some reason I quit listening to Brecker sometime after college. Then earlier this year I bought Brecker’s last album Pilgrimage after reading a glowing review. Brecker recorded Pilgrimage as he was [...]

Phil Haack has a great article on unit test boundaries. A unit test must not touch the file system, interact with a database, or communicate across a network. Tests that break these rules are necessary, but they’re not unit tests. With some hard thought, the code with external interactions can be isolated and reduced. This applies to both [...]

Yesterday I gave a presentation on designing clinical trials using adaptive randomization software developed at M. D. Anderson Cancer Center. The heart of the presentation is summarized in the following diagram. (A slightly larger and clearer version if the diagram is available here.) Traditional randomized trials use equal randomization (ER). In a two-arm trial, each treatment is given with [...]

Computerworld has a good article on why electronic medical records are so slow to appear. Many people I’ve talked to believe that medical data is just harder to work with than other kinds of data. They see the barriers to electronic medical records as primarily technical. That’s hard to swallow when nearly every other sector of [...]

John Udell pointed out today that Microsoft Outlook lets you edit the subject line on mail you’ve received, changing it to the subject line you wish the sender had used. So rather than maintaining a mental dictionary mapping irrelevant email subject lines to what they mean to you, you could just edit the subject line.

In my previous post, I speculated on why heights are normally distributed, that is, why their statistical distribution is very nearly Gaussian. In this post I want to point out where it breaks down. I’ll look closely at an example from Elementary Statistics by Mario Triola. At the beginning of the chapter, we noted that the [...]

The canonical example of the normal distribution given in textbooks is human heights. Measure the heights of a large sample of adult men and the numbers will follow a normal (Gaussian) distribution. The heights of women also follow a normal distribution. What textbooks never discuss is why heights should be normally distributed. Why should heights be [...]

Many well-known probability distributions converge to the normal distribution as some parameter or other increases. In a sense this is not very interesting: All roads lead to Rome. But though destinations are the same, the paths to the destination are varied and more interesting. I’ve posted notes on how the error in the normal approximation varies [...]

Steve at PowerShell Basics wrote a post about how to write ASP pages using PowerShell.

The C++ Standard Library Technical Report 1 (TR1) includes a specification for random number generation classes. The Boost library has supported TR1 for a while. Microsoft released a feature pack for Visual Studio 2008 in April that includes support for most of TR1. (They left out support for mathematical special functions.) Dinkumware sells a complete TR1 [...]

Software engineers typically use the term “horizontal scalability” to mean throwing servers at a problem. A web site scales horizontally if you can handle increasing traffic simply by adding more servers to a server farm. I think of horizontal scalability as scalability as the number of projects increases, rather than increasing the performance demands on [...]

Jeff Atwood had a good post today about database normalization and denormalization recently. A secondary theme of his post is scalability, how well software performs as inputs increase. A lot of software developers worry too much about scalability, or they worry about the wrong kind of scalability. In my career, scalability of computer processes has usually [...]

In the article Neo-Amish Drop Outs, Kevin Kelly shares a quote from Donald Knuth explaining why he (Knuth) seldom reads email. Rather than trying to stay on top of things, I am trying to get to the bottom of things. Getting to the bottom of things — questioning assumptions, investigating causes, making connections — requires a different [...]

I frequently need to look up how to add diacritical marks to letters in HTML, TeX, and Microsoft Word, though not quite frequently enough to commit the information to my long-term memory. So today I wrote up a set of notes on adding accents for future reference. Here’s a chart summarizing the notes. Accent HTML TeX Word grave grave \` CTRL + ` acute acute \' CTRL [...]

From time to time people speculate whether Einstein was an atheist. Richard Dawkins, for example, said in his book The God Delusion that Einstein was an atheist. However, Einstein addressed this point directly: I am not an atheist, and I don’t think I can call myself a pantheist. This quote comes from There Is a God by [...]

In the latest Windows PowerShell blog post Jeffrey Snover points to an earlier post he wrote about how to make PowerShell launch much faster. On my desktop, the time to launch PowerShell went from around 13 seconds to around 2 seconds after applying the fix Snover recommends.

I ran across this quote from John Tukey a couple days ago: An approximate answer to the right problem is worth a good deal more than an exact answer to an approximate problem. Too often approximate problems take on a life of their own and we forget that they were approximations. We worry about numerical results to [...]

The latest Science at NASA podcast explains how one might make a telescope on the moon out of local material. Peter Chen has constructed a prototype 12 inch telescope primarily using simulated lunar soil. He estimates a Hubble-sized telescope could be constructed from lunar soil and about about 130 pounds of material from Earth. Audio and [...]

The latest Pixel8 podcast has an interview with world-class debugger and former Green Beret John Robbins. John Robbins is a terrific speaker and author. In the podcast interview he gives some background on how he became an expert troubleshooter. He and shares some war stories of how he saved companies from bankruptcy by finding the bug [...]

Sometimes people demand a web application when a piece of paper would do just as well. People have thought I was out of my mind when I suggested a task could be done on paper at 1% of the cost of developing a custom web application. I guess paper is just vulgar. A typical web application [...]

On the Windows PowerShell blog, Jeffrey Snover links to a article in Linux Magazine by Narcus Nasarek comparing Windows PowerShell and Linux’s bash shell. The article’s sequence is unexpected. Not until near the end of the article does Nasarek get to the main difference between PowerShell and bash: PowerShell pipes objects, not text. Nasarek says regarding PowerShell’s [...]

CaringBridge offers “free, personalized websites that support and connect loved ones during critical illness, treatment and recovery.” The site is sponsored by donors, not advertising. When he was diagnosed with cancer four years ago, a friend of mine set up a password-protected web page to let us know the latest updates on his treatment and diagnosis. [...]

Wendell Berry on the publish-or-perish ethos of modern universities: If a tree falls in the absence of a refereed journal or a foundation, does it make a sound? The answer, in the opinion of the imitation corporate executives who now run our universities, is no. From Life is a miracle: an essay against modern superstition.

It appears that someone has found a flaw in Xian-Jin Li’s proposed proof of the Riemann hypothesis according to the Not Even Wrong blog. (Hat tip: Ars Mathematica) This doesn’t mean that all is lost. Andrew Wiles’ first attempt at proving Fermat’s Last Theorem was flawed, but he fixed it. Perhaps Li can patch his proof. [...]

Here’s a quote from a recent blog post from Tom Peters: You will be remembered in the long haul for the quality of your work, not the quantity of your work—the quantity part is just your defective ego talking—no one evaluates Picasso based on the number of paintings he churned out.

Xian-Jin Li claims to have proven the Riemann hypothesis, one of the most famous open problems in math. His paper is posted arXiv. The Riemann hypothesis is no obscure conjecture. It’s a natural question and central to number theory. For years mathematicians have been proving theorems of the form “If the Riemann hypothesis is true, then …” and [...]

I ran across the book Team Moon by Catherine Thimmesh when I took my kids to the library. The book’s subtitle is “How 400,000 People Landed Apollo 11 on the Moon.” This children’s book focuses on the thousands of people who worked behind the scenes of Apollo 11. It highlights some of the things that went wrong or [...]

I posted some notes this evening on working with probability distributions in Mathematica and R/S-PLUS. I much prefer Mathematica’s syntax. The first time I had to read some R code I ran across a statement something like runif(1, 3, 4). I thought it was some sort of conditional executation statement: run something if some condition holds. No, [...]