Ceaparu, IrinaLazar, JonathanBessiere, KatieRobinson, JohnShneiderman, BenWhile computers are beneficial to individuals and society, frequently, users encounter frustrating experiences when using computers. This study attempts to measure, through 111 subjects, the frequency, cause, and the level of severity of frustrating experiences. The data showed that frustrating experiences happen on a frequent basis. The applications in which the frustrating experiences happened most frequently were web browsing, e-mail, and word processing. The most-cited causes of the frustrating experiences were error messages, dropped network connections, long download times, and hard-to-find features. The time lost due to the frustrating experiences ranged from 30.5% of time spent on the computer to 45.9% of time spent on the computer. These disturbing results should be a basis for future study. (UMIACS-TR-2002-51) (HCIL-TR-2002-11)en-USTechnical Report