The more users' expectations prove right, the more they will feel in control of the system and the more they will like it.
Jakob NielsenInadequate use of usability engineering methods in software development projects have been estimated to cost the US economy about $30 billion per year in lost productivity.
Jakob NielsenThe system should speak the users' language, with words, phrases and concepts familiar to the user, rather than system-oriented terms. Follow real-world conventions, making information appear in a natural and logical order.
Jakob NielsenThroughout this book, we've been evangelizing simplicity, but ironically, the practice of simplicity is not simple. It is easy to build a bulky design by adding layer upon layer of navigation and features; it's much more difficult to create simple, graceful designs. Paring designs to essential elements while maintaining elegance and functionality requires courage and discipline.
Jakob Nielsen