Keep It Simple
Today, with the ever growing spread of computers into our daily lives, software application design is focusing more and more on untrained and casual users. These users have very different requirements to professional users, who have for a long time dominated the business scene. Developers must take this new breed of users seriously and design applications that do not frustrate them.
Simplicity
Simplicity simply means that things are simple. However, making things simple is not an easy task in today's complex business environments. Simplification is a continuous struggle between task requirements and user requirements. Form the users' point of view an application should be simple in the sense that it does not build up a barrier between them and their tasks. It should be nearly "invisible" to users and enable them to focus on their tasks.
Transparency
Users should always understand what is going on in an application with respect to their tasks and the required steps to take - not with respect to the inner working of the application. This is the essence of transparency! For example, users should always know the state of their task, what to do next, where to go next, what the consequences of certain user actions are, and so on. Transparency has several aspects. It relates to the overall structure of an application, as well as to the structure of the navigation, procedures and functionality in general.
Effectiveness & Efficiency
Is the primary goals for any software in a business environment. Effectiveness means that your application does what you designed it for, and that users accomplish their goals with your application. Efficiency requires that performance is fast and error-free. Both goals also have to be viewed with respect to the prospective users of your application. Users may vary in their skills and abilities and thus require different user interface designs.
