Lecture date: 22 Sept 2005
In the area of usability, standards can be broadly categorised as shown in the table.
|standard category||examples of relevant standards|
|Product use (effectiveness, efficiency and satisfaction in a particular context of use)||ISO 9241-11 Guidance on Usability ISO/IEC 9126-1 Software Quality Characteristics|
|User interface and interaction||ISO 9241 Ergonomic requirements for office work with visual display terminals, parts 10-17|
|Product development process||ISO 13407 Human-centered design processes for interactive systems|
|Capacity of an organisation to apply user centred design||ISO TR 18529 Human-centered lifecycle process descriptions|
Product use standards describe recommended usability measures such as task time and ergonomics. This is a ‘black box’ approach in that only the resulting usability is measured. In contrast, standards related to the user interface and interaction get into the nitty gritty of icon symbols and functions.
Standards for process quality usability apply an approach similar to the Capability Maturity Model (CMM) of software engineering. ISO 15504 (SPICE), for example, defines design capability levels. “In many organisations, first you design the product then you layer on the UI,” says Bevan; “the user-centered approach integrates design for usability into the overall design process and treats it as an integrated whole rather than an afterthought.”
A promising new initiative is the Common Industry Format (CIF) developed by the National Institute of Standards and Technology (NIST) in the US. Suppliers such as IBM, Microsoft, HP and Oracle are providing standard usability test reports to IT purchasers. CIF encourages suppliers to work more closely with purchasers to understand user needs.
Not everyone is happy with usability standardisation, however. According to Bevan, one major consumer electronics company has opposed attempts at usability standardisation for consumer products (ISO DIS 20282 Ease of operation of everyday products), claiming that “the results could be misinterpreted.”
Bevan and the audience agreed that standardisation of consumer products is woefully inadequate; the consumer only really discovers how usable a product is after it has been purchased and by then it’s often too late. So, although much progress has been made, it’s still early days for usability standardisation.