User interface design

User interface design

Interface design must center on usability, and user must participate in the design process. It is not possible usable interfaces without some experimention. Few people can anticipate how user will react to an interface and consequently one cannot expect to design an acceptable interface  directly from user requirements. Instead, the design becomes iteractive, with experimentation and testing, until a suitable interface is produced. Such experimentation must be integrated with the  development cycle.

Interface design can thus be quite a complex and laborious process unless we have tools that enable us easily to construct trial interface and quickly change them. Such experimentation is not possible if each new trial requires us to write programs for the presantation, as well as to program the often complex dialogs between the user and computer. Often compromises are made in designing screens to reduce programing cost, but these may result in reduced interface effectiveness. Effective interfaces can only be designed by using high-level tools for defining interfaces without such laborious programing. Such tools are now becoming available.

Basic layer-window support or menu support

Presentation layer-allow user to define presentations particular to their problem

Dialog layer-allow user to define dialogs for their particular problem

Reference
Introduction to System analysis and design-4th edition-Igor Hawryszkiewycz