"A user interface is well-designed when the program behaves exactly how the user thought it would".
Features of good UI:-
Must be designed considering the user profile.
Use of easy components that fairly easy to understand.
Allowing undo of an action.
Prompting user for warnings and precautions.
Minimal usage of too many clicks or buttons.
Maintaining consistency throughout the application with respect to Menu items, color, look and feel.
Provide shortcuts to get a task done.
Avoid spelling and grammatical mistakes.
9.User familiarity: copy well-known features from other programs.
10.Consistency: do similar operations in the same way.
11.Choose default values carefully: minimise the number of choices novice
users have to make.
12.Use metaphors: to establish the user’s conceptual model.
13.Recover-ability: ensure UNDO works in every situation.
14.Provide help: but (!) make it sparing and highly context specific.