ThEEffEctivEnEss, EfficiEncy, and satisfaction with which usErs can achiEvE tasks in a particular EnvironmEnt of a product. High usability mEans a systEm is: Easy to lEarn and rEmEmbEr EfficiEnt, visually plEasing and fun to usE and quick to rEcovEr from Errors. Ef="http://www.orrnEt.com/">. (1999-04-01)
