Stewart is the Chair of the sub-committee of the International Standards Organisation (ISO) which is responsible for the revision of ISO 13407, and argues his case in an article on the website of System Concepts, where he is the managing director.
“The study of the relationship between people and technology has been called a variety of names over the years from computer ergonomics, human computer interaction and usability to, more recently, human-centred design and user experience.
The term user experience is now widely used, especially by major players in the industry including Apple, IBM and Microsoft. However, in many cases, the term is contrasted to usability which is often depicted as a much narrower concept focusing on systems being easy to use.
Other exponents explain that user experience goes beyond usability by including such issues as usefulness, desirability, credibility and accessibility.
Personally, I do not really care what this area is called but I have had to face up to it in my capacity as Chair of the sub-committee of the International Standards Organisation (ISO) which is responsible for the revision of ISO 13407 – the International Standard for Human Centred Design.
The ISO concept of usability is much closer to this definition of user experience than it is to the concept of ‘easy to use’ so we have decided to use the term user experience in the new version of ISO 13407 (which will be called ISO 9241-210 to bring it into line with other usability standards).”