A Theory of Human-Computer Interaction

The Trouble With HCI

Human-Computer Interaction (HCI) as a discipline is drifting. It has no long-term objectives and no strategic direction. This would be forgivable if, like other disciplines, it had methods which were widely accepted as being likely to produce increases in understanding. But HCI has no such methods. It is not possible to say that HCI is a science, it is barely possible to describe it as an engineering discipline and yet we, as practitioners, are reluctant to relegate it to the status of a craft.

Part of the difficulty appears to be that it is hard to identify the “core” subject-matter of HCI. This is often acclaimed by practitioners as a benefit because it leads to the need for a multi-disciplinary approach which is considered to be a good thing. Yet without an identifiable subject-matter, it is difficult to identify what are the important issues in HCI, it is hard to say what an appropriate method for studying or practicing HCI would be and it is impossible to develop a theory of HCI.

This last is of peculiar importance. If we could produce a theory of HCI (whatever that might be), it would at the same time tell us what HCI is (as defined by the theory) and what its scope is. If we could say what the core subject-matter of HCI was, we would, at the same time, be proposing something like a theory of HCI. The problem of finding a theory of HCI is clearly what Rittel and Webber called a “wicked problem”. That is, finding a way to understand the problem is tantamount to finding a way to solve it. The way to tackle the problem then is to break the vicious circle by creating a theory of HCI. This would then seed a process of elaboration and refutation which would eventually end in there being a theory (or set of theories) of HCI which were acceptable to practitioners in the field—almost regardless of the quality of the original.

What Would a Theory of HCI Look Like?

The definition of a theory used here is a little idiosyncratic but it is one that should seem familiar to HCI people. I would like to propose that a theory is the set of rules that defines the behaviour of a system of conceptual objects and relationships. The set of conceptual objects and relationships itself, I will call a conceptualisation and we can imagine that there could be an arbitrary number of theories for any particular conceptualisation as well as there being an arbitrary number of conceptualisations for any field.

A Conceptualisation

A conceptualisation belongs to a field just as a theory does. It describes in detail the objects that are important to the field and the relationships between them. In the field of HCI we could imagine a conceptualisation involving objects such as “user”, “computer”, “input device”, “data” and so on, and relationships between them such as “display”, “use”, “enter”, etc.. Yet there is an arbitrary number of other conceptualisations for the same field. If one were to read the HCI literature and attempt to extract the conceptualisation used by the author in each separate paper, a large set of more-or-less complete, vague, overlapping and coherent conceptualisations would be the result.

To some extent, it will be possible to say that some conceptualisations are “better” than others and we can imagine dimensions along which to judge them such as completeness of coverage of the field, the degree of discrimination or granularity of the concepts and the extent to which practitioners in the field will agree with the conceptualisation. However, it is also true that some conceptualisations may be better than others for different purposes and that many may be equally good for the same purpose. Nevertheless, I feel that the lack of a clearly articulated common conceptualisation for HCI is a significant problem for the field. It hinders communication within and outside the community of practitioners and it effectively blocks the development of theory.

A Theory

A theory is the set of rules that governs the behaviour of the system described by the conceptualisation. In Newtonian mechanics, for instance, the three laws of motion are examples of such rules.

It is unlikely that a theory of HCI would ever have the simple elegance of a physical theory. The conceptualisation of HCI is, to begin with, far more complex than the conceptualisation of space and mass. Additionally, the individual concepts are themselves considerably more complex than those found in physics. Contrast typical HCI concepts such as “user”, “display” and “message” with concepts from Newtonian physics such as “mass”, “distance” and “time”. Nevertheless, it is still conceivable that such a theory could be built—even if the rules were far more elaborate and commonly involved the use of qualification and uncertainty.

Repositioning Usability

Anyone who has worked in the field of user inteaction design will know what a hard sell it is in all but the most enlightened of organisations. IT departments and IT services companies are often the most resistant customers. Why is that?

Well, I believe that, after 25 years in the business, I've finally worked it out. Below is the abstract and conclusion from a paper I've just written on the subject. The full text can be found at:

http://graham.storrs.cantalibre.com/compulsion/repositioningusability.html

ABSTRACT
In the IT services industry the various specialisms which deal directly with usability are generally considered of little value – in fact, of so little value that they are dispensed with entirely in the great majority of development projects. Some efforts have been made to cost-justify usability but IT suppliers and customers remain unconvinced. This discussion paper argues that the main reason for the perception of the low value of usability is because it is incorrectly regarded as a property of IT systems. The paper argues that a more realistic view- and one that accords better with best practice in the field - is that usability is a property of business processes. In particular it characterises the quality of the communication of the people participating in these process with the tools, equipment and media they use to assist them.
CONCLUDING REMARKS
It is clear to almost everyone that the software services industry is not doing a good job for its customers. It is also clear that, despite some inroads into product development, usability is not thought to offer much of value, even to an industry in such disarray. I contend that this is because the services which usability professionals are offering tend to have very low intrinsic value except in the area of task redesign. Task redesign, I argue, is the same as business process redesign. In this area, usability professionals have a huge contribution to make because process engineers have largely neglected the issue of process usability. Usability professionals have developed an extensive collection of task analysis and design approaches that help ensure process usability and these methods and techniques could profitably be adopted in industry. Beyond even this, the use of iterative prototype and evaluate cycles to create usable processes, has the potential greatly to improve process quality. Finally, I have argued that, to make use of these methods and techniques, organisations must radically change the way they procure IT projects. Specifically, they should fully specify their business processes, down to the level of a detailed interaction design, which would then form the basis of an IT procurement.