USER INTERFACE DEVELOPMENT
The user interface is all the screens, elements and actions that allow users to communicate with software.
User interfaces should be intuitive, forgiving and consistent in their design.
Processes that take some time to complete should provide feedback to the user.
The design of the user interface to most users is the most significant consideration when purchasing and continuing to use a software product.
Software developers must recognise this when developing new products.
Users often evaluate software primarily on the merits of its user interface.
This is natural and to be expected. After all, the user interface is their method of communicating with the program. Users do not need to understand the processing going on behind the scenes. For example,
when we print a document from a word processor we don’t consider the vast amounts of processing occurring. The word processor must convert the document to a form that can be understood by the printer’s driver. The driver must then turn this data into a form the printer understands and progressively send it to the printer. From the user’s perspective the document just prints, with perhaps some feedback displayed on the screen.
Developers view software from a different perspective. They must be aware of the underlying processes occurring. Most of the work involved in developing software concerns the correct planning, design and implementation of these processes. It is natural and right that developers concentrate on such matters. However, the user interface cannot be ignored if software products are to be a success for their users. The development team must include users as integral and important resources when developing software. This is particularly crucial when designing and creating the user interface.
Effective user interfaces meet the needs of users. Many of these needs will be specific to the current project being developed, others relate to more general aspects of good effective user interface design.
In this section we examine a number of general points that should be considered when developing effective user interfaces. For convenience these points have been grouped under subheadings. Be aware that each aspect of the user interface will affect other aspects of the interface.
For example, poor grouping of information will likely lead to more error messages. These error messages must be legible and make appropriate use of white space.
Factors affecting readability
- use of white space
- judicious use of colour and graphics
- grouping of information
- legibility of text
Prompts and messages
- effective prompts
- unambiguous and non-threatening error messages
- provision of feedback
Consistency of design
(see chapter 1, pages 25-32)
The most important aspect of user interface design is consistency. Consistency within the application’s screens and consistency between applications. In chapter 1, (see pages 26) we considered consistency of the user interface in regard to ergonomics.
Consistent user interfaces are easier to learn and are therefore easier to use. Skills learnt using other applications can be reused. The result being a more ergonomically sound application.
Each of the items examined in this section should be used consistently.
Readability is greatly increased when user interfaces make consistent use of white space, colour, graphics, grouping and text. Prompts and messages should be consistent. Users should be able to predict the result of their actions. Consistency of user interface design promotes this ability in users.
Social and ethical issues
(see Davis Prelim SDD Text book, chapter 1, in particular pages 35-39)
In 8.1.1, we examined social and ethical issues in detail. From the user’s perspective, the user interface is the most vital component of most new software products. Thus, many of the issues in chapter 1 relate to user interface design.
Developers have a responsibility to ensure social and ethical issues are considered and dealt with during the design and development of the user interface.
