From usability engineering to interaction design

Turkka Keinonen

Usability is the concept that has established its position for linking a human angle to information and communication technology. The complexity of new technologies alienating a part of population from active society members, personal frustrations with hard to approach and difficult to use devices, the threat of the information technology giving the control of decision making to those who master the technology are all expected to be prevented by usability. Usability carries big promises, there are huge expectations towards the capabilities of usability.

There are several connotations to the concept of usability depending on the context: it can be a set of measurements, a set of product attributes, or a whole discipline. On one extreme there is the omnipotent shield which can be used to cover a wide range of different activities that are related to new technologies, people using them, the contexts of use, or any broader framework around people facing technologies. On the other end there is the rather limited technical core definition of the usability concept as a set of measurements, i.e. ISO 9241, that are carried out typically as laboratory tests.

The narrow core definition is too limited to explain phenomena and support design and research activities when social, business, cultural, emotional, etc. aspects are dealt with. Simultaneously the promise and challenge of the wide definition is so stimulating that it cannot be abandoned. Consequently, there has been several attempts which have tried to challenge the technical, cognition based usability, but enjoyed the good reputation of wide one. Different challenging attemps have had different drivers.

Challenging the concept can be used to get more power and influence on decision making. As core usability is mainly related to evaluation, it becomes important only when there is something to evaluate. It may happen that all the important decisions have been made at that point when usability tests can start. So, one natural direction to broaden the concept is to go to activities that precede test in product development, i.e. user studies and interaction design. By adopting these kind of activities usability people are able to take more initiative in product development.

Another reason for going beyond usability is the changed evaluation framework of human-product interaction as information technology has spread from business use to everyday products. Efficiency and effectiveness are not any more the core criteria describing the 'quality of use'. The human-product interaction needs to be considered in contexts where the experiences the products provide, not in isolation, but in social contexts are in focus. The experiences can only be explained if emotional, aesthetical, social, etc. factors are included. These new dimensions are not easily operationalised and often call for creative approaches to interaction. The design orientation in the field of human-device interaction increases.

Third, different research disciplines see the phenomena around new technologies and people applying it - and it changing their patterns of behavior - interesting and worth of studying. Because the focus is not on the technology as such, but on how people adapt it, produce it, value it, etc. these approaches fit well under the broad usability umbrella.

As usability, independent of the angle, is related to technology, links to product development are extremely essential. People representing different views to usability tend to criticize product development processes for having too limited angles to usability. This can be seen as an indication of progress. Product development used to be criticized for not including usability studies, now it is being criticized for the quality of the usability.

One of the most characteristical restrictions in product development is the lack of time and resources. The designers need to focus on the most essential. This applies to usability as well, because all supplementary spheres of it cannot be applied. However, the cognitive approach is not always the right one. Other angles may illuminate some of the design problems much better. Thus, usability experts and interaction designers need to move from a world where usability was a set of rather simple methods presented in well written handbooks to a world where usability considerations are required in range of problems, where the nature of these considerations change, and where it is essential to be able to select the right approach depending on the nature of the problem. Sometimes design initiative is needed to make the issue more concrete. In another case sociological approaches put the phenomenon into a relevant relationship with other issues. In the third case the cognitive behavioral approach is required to ensure the understandability of details.

Doctor of Arts Turkka Keinonen is principal scientist and interaction designer at Nokia Research Center. He has published two books on usability design issues, One-dimensional Usability, 1998 and Miten käytettävyys muotoillaan (How to design usability), 2000.