tailieunhanh - Software Engineering A PRACTITIONER’S APPROACH phần 6

Giao diện người dùng được cho là yếu tố quan trọng nhất của một hệ thống dựa trên máy tính hoặc sản phẩm. Nếu giao diện được thiết kế kém, khả năng của người sử dụng để khai thác sức mạnh tính toán của một ứng dụng có thể bị cản trở. Trong thực tế, một giao diện yếu kém có thể gây ra một ứng dụng khác được thiết kế tố | 418 PART THREE CONVENTIONAL METHODS FOR SOFTWARE ENGINEERING SUMMARY The user interface is arguably the most important element of a computer-based system or product. If the interface is poorly designed the user s ability to tap the computational power of an application may be severely hindered. In fact a weak interface may cause an otherwise well-designed and solidly implemented application to fail. Three important principles guide the design of effective user interfaces 1 place the user in control 2 reduce the user s memory load and 3 make the interface consistent. To achieve an interface that abides by these principles an organized design process must be conducted. User interface design begins with the identification of user task and environmental requirements. Task analysis is a design activity that defines user tasks and actions using either an elaborative or object-oriented approach. Once tasks have been identified user scenarios are created and analyzed to define a set of interface objects and actions. This provides a basis for the creation of screen layout that depicts graphical design and placement of icons definition of descriptive screen text specification and titling for windows and specification of major and minor menu items. Design issues such as response time command and action structure error handling and help facilities are considered as the design model is refined. A variety of implementation tools are used to build a prototype for evaluation by the user. The user interface is the window into the software. In many cases the interface molds a user s perception of the quality of the system. If the window is smudged wavy or broken the user may reject an otherwise powerful computer-based system. REFERENCES LEA88 Lea M. Evaluating User Interface Designs User Interface Design for Computer Systems Halstead Press Wiley 1988. MAN97 Mandel T. The Elements of User Interface Design Wiley 1997. MON84 Monk A. ed. Fundamentals of Human-Computer Interaction .