Monthly Archives: November 2008

Five criticisms of significance testing

The follow list summarizes five criticisms of significance testing as it is commonly practiced. Andrew Gelman: In reality, null hypotheses are nearly always false. Is drug A identically effective as drug B? Certainly not. You know before doing an experiment

Tagged with:
Posted in Statistics

Creativity for left-brained people

I’ve written a fair amount about creativity on this blog, though I’ve written much more about other topics. I created a Squidoo lens to pull together some of my creativity posts. Maybe some people will enjoy that page who would

Posted in Uncategorized

Fast way to test whether a number is a square

A question came up on StackOverflow today regarding testing whether integers were perfect squares. The person asking the question said his first idea was to take the (floating point) square root, round the result to the nearest integer, square that,

Tagged with: , ,
Posted in Computing, Math, Science, Software development

Origin of "statistically significant"

The words signify and signal come from the Latin word signus for sign. The phrase “statistically significant” was coined to indicate the existence of a statistical signal that an effect was present. The word significantin this context is not meant

Tagged with:
Posted in Science, Statistics

The shape of the moon's orbit around the sun

Michael Lugo pointed out this article explaining why the shape of the moon’s orbit around the sun is not what you might expect.

Tagged with: ,
Posted in Math, Science

10,000 spam comments blocked

The spam filter on my blog has now blocked over 10,000 comments since I installed it. As far as I know, there have only been a couple false positives (legitimate messages flagged as spam). Occasionally I’ll skim the blocked comments

Posted in Uncategorized

A pragmatist takes the witness stand

The idea for my previous post was the following quote from Josias Royce responding to William James. James embraced philosophical pragmatism, the view that whatever is expedient is true. Would you then get on the witness stand in a court

Posted in Uncategorized

A relativist takes the witness stand

Here’s how a relativist would administer a judicial oath. Do you solemnly swear to tell what’s true for you, the whole of what’s true for you, and only what’s true for you? Would that make you feel a little uneasy

Posted in Uncategorized

Bizarre animal defense

60-Second Science has a story about a bizarre form of animal defense. There are caterpillars that vomit on attackers. And they don’t spew corrosive chemicals as animals sometimes do. They spew surfactants (think soap). Audio

Tagged with:
Posted in Science

When the normal approximation for Student t isn't good enough

Folk wisdom says that for all practical purposes, a Student-t distribution with 30 or more degrees of freedom is a normal distribution. Well, not for all practical purposes. For 30 or more degrees of freedom, the error in approximating the

Tagged with:
Posted in Statistics

Architects versus engineers

Here’s a quote I ran across in the book Operating Systems. When an engineer builds a building, it’s very well built, but it’s so ugly that the people tear it down; when an architect builds a building, it’s very beautiful,

Tagged with:
Posted in Uncategorized

Errors in math papers not a big deal?

Daniel Lemire wrote a blog post this morning that ties together a couple themes previously discussed here. Most published math papers contain errors, and yet there have been surprisingly few “major screw-ups” as defined by Mark Dominus. Daniel Lemire’s post

Tagged with: ,
Posted in Math, Software development

Upper and lower bounds on binomial coefficients

Binomial coefficients are easy to motivate and define. In its simplest form, the binomial coefficient (n, k) is the number of ways to choose k things from a set of n things and equals n!/(k! (n-k)!). On the other hand,

Posted in Math

HTML parsing landmines

Phil Haack explains why parsing HTML isn’t as easy as it sounds in The Landmine of Parsing HTML and Stripping HTML comments. Update: Phil Haack’s follow-up post.

Tagged with:
Posted in Software development

Inside Steve Jobs' brain

Last week I read Inside Drucker’s Brain and this week I’m reading Inside Steve’s Brain. The two books are written by different authors about very different men. But one theme that both books have in common is an appreciation for

Tagged with: ,
Posted in Business