Avionics, datelines, and shopping carts

The Risks Digest (volume 24, issue 58) described the F-22 Raptor software glitching at the international date line when the planes were going from Hawaii to Okinawa. Pretty interesting (and there is a footnote about the apocryphal F-16 that flipped crossing the equator). Someone who worked on the F-22 system responded to the reports.

Another short, interesting article is in the September 2007 IEEE Computer. "Online experiments: Lessons learned" is about testing prototype interfaces and systems. Here's two paragraphs:

Experimenters often ignore secondary metrics that impact the user experience such as JavaScript errors, customer-service calls, and Web-page loading time. Experiments at Amazon.com showed that every 100-ms increase in the page load time decreased sales by 1 percent, while similar work at Google revealed that a 500-ms increase in the search-results display time reduced revenue by 20 percent.

You can read it here (or if you want to see the official citation, it's here).

Speaking of JavaScript, Jim Horning noticed his typing deteriorating, so went to a doctor for neurological testing. The diagnosis was IE 7. See his message and follow-up. All you really need is a mid-1980s Mac anyway.