Resume Contact  
  > what is usability?
  > Usability Glossary
^ My Resources
Home > My Resources > User Centered Design principles
The basic and the most simple principle of User Interface design is to make the user feel in control of the software/system, rather than feeling the controlled by the software/system. The basic forms of interaction your software/system should support are listed below.

The Design of the software should be such that users can directly manipulate software representations of information. Whether they are dragging an object to relocate it or navigating to a location in a document, users should see how their actions affect the objects on the screen. Visible information and choices also reduce the user's mental workload. Users can recognize a command more easily than they can recall its syntax.

Metaphor used to label any element of system, should provide direct and intuitive interface for user tasks. Metaphors used should be in such a way that the user can predict and learn to adapt the system for software based representations. The purpose of using metaphors is to provide a cognitive bridge; the metaphor is not an end in itself. Further more the metaphor used can help the user to associate the meaning with a familiar object, than they remember the syntax for that particular command. Metaphors support user recognition rather than recollection.
It allows the user to map the existing knowledge to new tasks in the new interface. This assists the user to learn new things more easily and comfortably. The main reason for this being, that the user need not spend time remembering and comparing the differences in interaction. By establishing a sense of stability and harmony in the interfaces, consistency helps the user to be familiar and predictable about the interface.

Consistency with application, by using the same commands to carry out tasks, that seems similar to the users. In case of printing the document, Print command prints the document; obviously, the user can predict what’s going to happen, when this command is executed or button is clicked. Consistency in visual elements, icons represent the set of instructions, which can be easily visualized by the user. For instance, when using icons in the applications care should be taken so that visual icons comply to the functionality of the application. Consistency in visual terms can also be considered by using icons that represent real life objects. For eg. Using the Trashcan icon for storing deleted files/items from the application, here the trashcan can help user recognize the effect of the delete function.
Users most of the times like to explore and learn new things. They always starts to learn things with trial and error method, this behavior initiates another important principle, Forgiveness. The interface provides appropriate set of choices and warns them at various stages about the potential situations, where they can damage the data or system. Moreover, the system makes data reversible and recoverable. There are situations where, even in using the best systems users can commit errors/mistakes by clicking something un-intentionally which can be physical mistake or mental mistakes by making wrong decisions about command or data to select. An effective designed can avoids such situations that can result in errors. It accommodates potential users errors and makes it easy for the user to recover.
Users need to get instant feedback about their actions. Informative and real time feedback is mostly desired. Effective feedback is such that it is timely and is presented as close as the users interaction as possible. There are instances when the user has to wait for a while to let the system process the interaction, at this stage the most disconcerting part would be viewing the blank screen that is unresponsive at that point of time.
  Meher Kanth Kanigiri
Mobile: +91 9866504249
Copyright © 2011. Meher Kanigiri. All rights reserved.