Viruses, hardware crashes, dropped phone lines, software bugs and slow connections cause computer users to lose almost half of their productive time, says professor Ben Shneiderman, founding director of the University of Maryland’s human-computer interaction lab.

The lab studied 111 savvy PC users and found that time lost due to frustrating experiences ranged from 30 percent to 46 percent of the 2.6 hours each person spent on the computer.

“They were mainly students who were used to computers and yet nearly half their time was wasted. People in the industry say that can’t be true, and yet when I tell public audiences they aren’t surprised at all.”

Shneiderman’s new book, Leonardo’s Laptop: Human Needs and the New Computing Technologies, aims to dramatically raise the expectations of the public and push the IT industry to do better. “These are non-trivial issues and we should expect higher performance,” he said.

Shneiderman says universal usability is also a vital goal. Software should be useable across all languages and devices new or old, and information should be accessible across all connection speeds.