This document discusses principles of user interface design for graphical user interfaces, web interfaces, and intranets. It defines key terms like user interface, input, output, and highlights the importance of good design. Benefits of good design include reduced errors, training costs and increased satisfaction. Characteristics of graphical interfaces are discussed like visual presentation, pick and click interaction, and object orientation. The popularity and differences between GUIs, the web, printed pages and intranets are also summarized.