Design_Principle

Visibility The importance of visibility of our two very different examples voice mail system to the presence and number of waiting messages invisible, and made to answer these two machines highly visible. More obvious features, the more likely users will be able to know how to do the next step. In contrast, when functions are "out of sight," which makes them more difficult to find and know how to use. Norman described the control a car to emphasize this point. For the control of the operation is clearly different visible (for example, indicators, lights, horn, hazard warning lights), to what can be done. Between the control relationship has been positioned In the car and they do makes it easy for drivers to find a suitable control or the task at hand. Feedback The concept of visibility related to feedback. This is best illustrated by what daily life would be like without it metaphor. Imagine playing a guitar with a knife sliced bread, or use a pen to write the action, did not produce any effect if a few seconds. There will be an unbearable delay before the music making, bread is cut off, or words appear on paper, makes it almost impossible to continue under a puppet theater, saw, or stroke. Feedback is sent back on what action has been completed, the information has been achieved, so that the person to continue its activities. Various types of audio feedback is interaction design, tactile, language, vision, and the combination. Determine which combination of different types of activities and interactivities appropriate center. The correct use of feedback can also provide user interaction necessary attention. Mapping This refers to the mapping between the control and influence them in relationship to the world. Almost all of the cultural needs of a certain mapping between the control and whether the effect is a flashlight, automobile, power plant, or cockpit-like. Between the control and influence a good example of the mapping is up and down arrows used to indicate the cursor up and down movement, respectively, on the computer keyboard. The controls and their impact on the relative position of the map is also very important. Consider a variety of music devices (such as MP3, CD player, tape recorder). How to play, rewind control, fast-forward map to the desired effect' They usually follow a provision in the middle of the play button on the left and right side of the back button fast-forward button sequence, as mutually agreed. Consistency This refers to the design of the interface has a similar action, and use a similar task is to achieve similar elements. In particular, a consistent interface is as follows, such as using the same operating rules to select all objects. For example, a consistent operation is using the same input action to highlight any graphical interface objects, such as total clicks the left mouse button. The interface is inconsistent, on the other hand, allows an exception. An example of this is that some (for example, e-mail presented in the table) graphics object only by right, while all other operations are highlighted using the left mouse button. Inconsistency of such a problem with this is that it is quite arbitrary, making it difficult for users to remember and makes users more prone to errors Constraint Constraints of the design concept, is the kind of user interaction to determine the limit can occur at a time approach. This can be achieved with various ways. A common graphical user interface design practice is O to cancel the shadow of some of their menu options, which limits the user only action activities permitted at that stage. One of the advantages of this form of restraint is that it can prevent the option to select the correct user, thereby reducing the chance of mistakes. Graphical representation of the different types of use can also limit a person's problem or explain the information space. For example, the flow diagram shows the objects are related to them, thereby constraining the way information is perceived. Affordances Affordances is used to refer to an object, let people know how to use it attributes the term. For example, a mouse button invites pushing (in so doing activate the click) it is itself constrained in its plastic shell mode. In a very simple level, affordable means "to give clues" (Norman, 1988). When the suitability of a physical object perceived clearly, it is easy to know how to interact with it. For example, a door handle affords pulling, a cup handle affords grasping, and affords the mouse button push. Norman introduced the design of everyday objects in his discussion of the concept of the late 1980s. Since then, been much popularized, interface objects are used to describe how life D is designed so that they make clear what can be done to them. For example, such as buttons, icons, links and graphic elements about the scroll bar on how to make it obvious how they should use: Click on the icon design should be affordable, the burden of the scroll bar move up and down, the burden of pushing the button.