The General Conception pre-supposes an associated HCI Engineering Discipline (F1) comprising: HCI Engineering knowledge, which distinguishes the interactive system of user and computer, the tasks it performs as desired and the goodness of that performance in terms of specific criteria (C1) The practice is supported by HCI Engineering knowledge seeking to solve design problems. Design problems here include specification, followed by implementation, of users interacting with computers (the interactive system) to perform tasks as desired in some domain of application. (C3)
The HCI Engineering Conception, then, is unequivocally one of design practice. (F2) HCI Engineering practice is the product of research practice and design practice itself. Such practice is public and ultimately formal. (F3) It may assume a number of forms, for example, codified, proceduralised, formal etc, as in methods, theories, principles etc. It may be maintained in a number of ways; for example, it may be expressed in journals, learning systems, procedures, tools, methods etc. HCI Engineering practice is, therefore, a necessary characteristic of the HCI Engineering Discipline. (C2)
The discipline of HCI Engineering, aims (in the longer term) to solve its general problem of design by the specification of designs before their implementation – as in ‘specify then implement’ design practices. (C6) (C7) (C9) The latter is made possible by the prescriptive nature of the knowledge supporting such practices – knowledge formulated as HCI Engineering methodological (and substantive) principles. (C4)
However, a pre-requisite for the formulation of any HCI Engineering principles is a Conception. The Conception, from which the HCI Engineering Conception is generalised, is a unitary view of the HCI Engineering design problem; its power lies in the coherence and completeness of its definition of the concepts, which can express that problem. (F4) (C8) (C12)
Engineering principles are articulated in terms of those self-same concepts. The latter include: user; computer; interaction; task; domain of application; system; and desired performance (for a full listing – see 2.2).
Thus, the Conception of HCI Engineering methodological (and substantive) principles assumes the possibility of a codified, general, and testable formulation of HCI Engineering discipline knowledge and practice. The latter might be prescriptively applied to designing humans and computers interacting to perform tasks as desired. Such principles would be unequivocally formal and operational. Indeed, their operational capability would derive directly from the formality of their concepts. (C4) HCI Engineering methodological (and substantive) concepts would be generalisable over classes of design problem solutions. Since the principles are operational, their application (expressed as design solutions) would necessarily be specifiable. They would also be testable and so their reliability and generality could also be specified. (C5)
In this way would the principles, expressed in terms of the Conception of Engineering design practice, be validated Such validated Engineering methodological (and substantive) design principles would offer a better guarantee (that is, more assurance – see 3.6.1)) of solving the HCI general design problem. Better, for example, than the experiential trial-and-error practice of craft HCI or the guidelines/heuristics and methods of Applied Science HCI. (C11)
HCI Engineering principles, following the Conception of Engineering design practice, can be methodological and substantive. Methodological principles prescribe the methods for solving the general HCI design problem. Methodological principles would assure complete specification of all necessary levels of design solution representation. Substantive principles prescribe the features and properties of HCI systems that constitute solutions to the HCI Engineering design problem. (C10)
The extent, to which HCI engineering principles might be realiseable in practice, in the longer term, remains to be seen and demonstrated. In the meantime, craft practice (F5) in whatever form – models, methods, heuristics, guidelines, experience, procedures etc cannot be other than recruited to solve HCI design problems both by researchers and practitioners. (C13)
Key concepts are shown in bold on their first appearance only.
Footnotes and CitationsFootnotes
(F1) The contrast here with Engineering is Science, which has its own discipline problem, knowledge and practices.
(F2) See (F1)
(F3) For the present purposes, Engineering, in its early craft stages, is not addressed.
(F4) Other HCI Engineering conceptions, other than that of the EU, might, of course, also be postulated.
(F5) See (F3)
Citations
Long and Dowell (1989)
(C1) ‘The framework expresses the essential characteristics of the HCI discipline, and can be summarised as: ‘the use of HCI knowledge to support practices seeking solutions to the general problem of HCI’. (Page 9, Lines 16-19)
(C2) ‘All definitions of disciplines make reference to discipline knowledge as the product of research or more generally of a field of study. Knowledge can be public (ultimately formal) or private (ultimately experiential). It may assume a number of forms; for example, it may be tacit, formal, experiential, codified – as in theories, laws and principles etc. It may also be maintained in a number of ways; for example, it may be expressed in journals, or learning systems, or it may only be embodied in procedures and tools. All disciplines would appear to have knowledge as a component (for example, scientific discipline knowledge, engineering discipline knowledge, medical discipline knowledge, etc). Knowledge, therefore, is a necessary characteristic of a discipline.’ (Page 11, Lines 30-38)
(C3) ‘The discipline of engineering may characteristically solve its general problem (of design) by the specification of designs before their implementation. It is able to do so because of the prescriptive nature of its discipline knowledge supporting those practices – knowledge formulated as engineering principles.’ (Page 24, Lines 11-14)
(C4) ‘The conception of HCI engineering principles assumes the possibility of a codified, general and testable formulation of HCI discipline knowledge which might be prescriptively applied to designing humans and computers interacting to perform work effectively. Such principles would be unequivocally formal and operational. Indeed their operational capability would derive directly from their formality, including the formality of their concepts.’ (Page 24, Lines 28-31)
(C5) ‘First, HCI engineering principles would be a generaliseable knowledge. …….. Second, engineering HCI principles would be operational, and so their application would be specifiable…….. Because they would be operational, they would be testable and their reliability and generality could be specified.’ (Page 27, Lines 20-22 and 36-28)
Dowell and Long (1989)
(C6) ‘The paper .….. examines the potential for Human Factors to formulate engineering principles. ……… A conception would provide the set of related concepts which both expressed the general design problem more formally, and which might be embodied in engineering principles.’ (Page 1513, Lines 9 and 10)
(C7) By comparing the HF general design problem with other, better-understood, general design problems, and by identifying the formal knowledge possessed by the corresponding disciplines, the potential for HF engineering principles is suggested.’ (Page 1514, Lines 15-18).
(C8) ‘However, a pre-requisite for the formulation of any engineering principle is a conception. A conception is a unitary (and consensus) view of a general design problem; its power lies in the coherence and completeness of its definition of the concepts, which can express that problem. Engineering principles are articulated in terms of those concepts.’ (Page 1514, Lines 23-27)
(C9) ‘Generally, the established engineering disciplines possess formal knowledge: a corpus of operationalised, tested, and generalised principles. Those principles are prescriptive, enabling the complete specification of design solutions before those designs are implemented (see Dowell and Long, 1988b).’ (Page 1520, Lines 1-5)
(C10) ‘Engineering principles can be substantive or methodological. Methodological Principles prescribe the methods for solving a general design problem optimally. ……Methodological principles would assure each lower level of specification as being a complete representation of an immediately higher level. Substantive Principles prescribe the features and properties of artefacts, or systems that will constitute an optimal solution to a general design problem. (Page 1520, Lines 6-15)
(C11) ‘The contemporary HF discipline does not possess either methodological or substantive engineering principles. The heuristics it possesses are either ‘rules of thumb’ derived from experience or guidelines derived from psychological theories and findings. Neither guidelines nor rules of thumb offer assurance of their efficacy in any given instance, and particularly with regard to the effectiveness of a design. The methods and models of HF (as opposed to methodological and substantive principles) are similarly without such an assurance. (Page 1520, Lines 21-28)
(C12) ‘Such a conception ….. enables the formulation of engineering principles which embody and instantiate those concepts.( Page 1520, Line 1)
(C13) ‘The extent to which HF engineering principles might be realisable in practice remains to be seen. It is not supposed that the development of effective systems will never require craft skills in some form, and engineering principles are not seen to be incompatible with craft knowledge, particularly with respect to their instantiation. At a minimum, engineering principles might be expected to augment the craft knowledge of HF professionals. Yet the great potential of HF engineering principles for the effectiveness of the discipline demands serious consideration.’ (Page 1533, Lines 24-29)