人机界面第二章.ppt

Homework List main guidelines List main principles Consistency through grammars Consistent user interface goal Definition is elusive - multiple levels sometimes in conflict Sometimes advantageous to be inconsistent. Consistent Inconsistent A Inconsistent B delete/insert character delete/insert character delete/insert character delete/insert word remove/bring word remove/insert word delete/insert line destroy/create line delete/insert line delete/insert paragraph kill/birth paragraph delete/insert paragraph 2-* Consistency through grammars (cont.) Inconsistent action verbs Take longer to learn Cause more errors Slow down users Harder for users to remember 2-* The disappearance of syntax Users must maintain a profusion of device-dependent details in their human memory. Which action erases a character Which action inserts a new line after the third line of a text file Which abbreviations are permissible Which of the numbered function keys produces the previous screen. 2-* The disappearance of syntax (cont.) Learning, use, and retention of this knowledge is hampered by two problems Details vary across systems in an unpredictable manner Greatly reduces the effectiveness of paired-associate learning Syntactic knowledge conveyed by example and repeated usage ? Syntactic knowledge is system dependent  2-* The disappearance of syntax (concluded) Minimizing these burdens is the goal of most interface designers Modern direct-manipulation systems Familiar objects and actions representing their task objects and actions. Modern user interface building tools Standard widgets 2-* Contextual Theories User actions are situated by time and place You may not have time to deal with shortcuts or device dependent syntax, such as on mobile devices, when hurried Physical space is important in ubiquitous, pervasive and embedded devices, e.g. a museum guide stating information about a nearby painting A taxonomy for mobile device application developme