Human-Computer Interaction Standards

It is often assumed that a standard means a precise specification. Such standards have brought benefits in many fields, eg: bolts which screw into nuts, ATMs which can read credit cards, and compilers which can read programming languages. Some HCI standards are also of this type: many design guides provide a detailed specification of the nature of the user interface. Although standard user interfaces provide the benefit of consistency, they become out of date as technology changes, and are usually only appropriate for limited types of users and tasks (Bevan and Holdaway, 1993). Thus most work on international standards for HCI has not been about precise specification, but instead has concentrated on the principles which need to be applied in order to produce an interface which meets user and task needs. These standards broadly fall into two categories. One is a "top-down" approach which is concerned with usability as a broad quality objective: the ability to use a product for its intended purpose. The other is a product-oriented "bottom-up" view which is concerned with aspects of the interface which make a system easier to use. The broad quality view originates from human factors, and standards of this type are applicable in the broad context of design and quality objectives. The product-oriented view concentrates on the design of specific attributes, and relates more closely to the needs of the interface designer and the role of usability in software engineering (see Bevan, 1995). Section 4 explains how standards can be used to provide a means of meeting the requirements for the operator-computer interface in the European Directive on Display Screen Equipment.