Interface design is an iterative process. Interface design activities commences once interface analysis has been completed. Each user interface design occurs a number of times, each elaborating and refining information developed. Interface designer begins with sketches of each interface state and then work backward to define objects, actions, and other important design information.
APPLYING INTERFACE DESIGN STEPS
- Definition of interface objects.
- Defining the actions that are applied to them.
- Description of a use case is written.
- Once objects and actions are defined and elaborated, they are categorized by type.
- Target, source and application objects are identified.
- A source objects is dragged and dropped onto a target object.
- Application objects represents application specific data that is not directly manipulated as part of screen interaction.
- Screen layout is performed once all objects and actions are defined.
- Screen layout is interactive process in which graphical design and placement of icons, major and minor menus, screen text is conducted.
- Although automated tools can be useful in developing layout prototypes, sometimes a pencil and paper are all that are needed.
USER INTERFACE DESIGN PATTERNS
- A wide variety of user interface design patterns have emerged.
- A design pattern is an abstraction that prescribes a design solution to a specific well bounded design problem.
DESIGN ISSUES
Four common design issues are:
- system response time: it is measured from the point at which the user performs some control action. its two main characteristics are length and variability.If system response is too long, user frustration and stress is the result.Variability refers to the deviation from average response time.
- user help facilities: design issues must be addressed when a help facility is considered.
- error information handling: A good error message should describe problem in language that a user can understand. An error message should provide constructive advice for recovering from error. The message should indicate any negative consequences of the error. The error message should be accompanied by an audible or visual cue and the message should be non-judgmental.
- command labeling: Conventions for command usage should be established across all applications.It is confusing and often error-prone for a user to type command. The potential of error obvious.
Unnecessary iteration, project delays, and customer frustration often result. It is better to establish a design issue to be considered at beginning of software design, when changes are easy and costs are low.
No comments:
Post a Comment