Wednesday, May 28, 2014

Inkscape - Free vector graphics program

Vector graphics are great for producing high-quality illustrations for journal articles, but the programs I've used to date are either really expensive (Corel Draw, Adobe Illustrator) or rather limited (MS PowerPoint). So, today I tried Inkscape, a free, open-source, cross-platform vector graphics program. It seems pretty good and easy to use. Note that, on a Mac, keyboard shortcuts for this program use Ctrl rather than the more usual Cmd.

Friday, May 23, 2014

Bayesian contingency chi-square in R

One of the advantages of Bayesian statistics is that they permit discussion of null results. Antony Overstall of St. Andrews has recently released a package for R called conting that handles Bayesian analysis of contingency tables in a relatively straightforward way. . I had a play around with it and managed to get meaningful results in about an hour. Take a look!

Wednesday, May 21, 2014

Free teaching materials

Some of my teaching materials are now freely available on  Currently, you'll find some tutorials on R, a suite of software for 1st year practicals, and a formula booklet for first year stats courses. I'll add more when I have the time.

Tuesday, May 20, 2014

Some sobering statistics about psychological data

I've been catching up on some of the recent articles that have dealt with data quality issues in psychology. Here are three sobering statistics:

  1. By some estimates, only about 1% of papers published in psychology since 1900 have involved replications (Makel et al., 2012).
  2. Under certain not unreasonable assumptions, approximately one-third of published results in psychology may be false positives (Pashler & Harris, 2012).
  3. Even for recently published papers, approximately 70% of requests for raw data end in failure (Wicherts et al., 2006).
So, if your research depends on a previous result (and whose doesn't to some extent?), start your experiment series with a direct replication, and publish your raw data.

Friday, May 16, 2014

Travel website with office hours! a.k.a. Only In Academia

Trying to book a flight with the university's travel agent. It's already taken two days to get my budget code back on to their system. Today, I almost book a flight, but my passport is at home and I can't complete the booking without it. No worries, I think. I'll just make the booking when I get home. No chance. Clicking on my choice of flight, the website tells me I cannot proceed with this option because it is out of office hours. What, so the computers get to go home in the evenings !?!