The EU Conception of HCI Engineering Design Knowledge presupposes an associated HCI Engineering Discipline, comprising: HCI engineering knowledge, which distinguishes the interactive system of user and computer, the work it performs and the effectiveness of that performance, in terms of task quality and system resource costs. This HCI design knowledge supports HCI practices seeking to diagnose design problems and to prescribe design solutions to those problems. (C18)
The EU Conception of the HCI Engineering design problem is informally expressed as: to design human interactions with computers for effective working. The EU Conception, then, is unequivocally one of design knowledge. HCI Engineering knowledge, following the EU Conception, is the product of research. Such knowledge is public and ultimately formal. It may assume a number of forms, for example, codified, proceduralised, formal etc, as in theories, principles etc. It may be maintained in a number of ways, for example, it may be expressed in journals, learning systems, procedures, tools etc. HCI Engineering knowledge is, therefore, a necessary characteristic of the EU HCI Engineering Discipline. (C3)
The discipline of HCI Engineering, aims, following the EU Conception, (in the longer term (F1)) to solve its general problem of design by the specification of designs before their implementation – as in ‘specify then implement’ design practices. (C12) (C19) The latter is made possible by the prescriptive nature of the knowledge supporting such practices – knowledge formulated as HCI Engineering principles. (C21)
However, a pre-requisite for the formulation of any HCI Engineering principles is a Conception. The EU Conception 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. (C17) Engineering principles are articulated in terms of those self-same concepts. The latter include: user; computer; interaction; work; work domain; worksystem; effectiveness; performance; task quality; system resource costs etc (see 2.5 for a complete presentation of the EU design problem concepts, which would be recruited to the formulation of EU-conceived engineering principles. (C16) (C17) (F2)
Thus, the EU Conception of HCI Engineering principles assumes the possibility of a codified, general, and testable formulation of HCI Engineering discipline knowledge. The latter 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 the formality of their concepts. (C13) EU HCI Engineering 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. (C14)
In this way would the principles, expressed in terms of the EU Conception of Engineering design knowledge, be validated. Such validated Engineering design principles would offer a better guarantee (that is, more assurance) of solving the HCI general design problem. Better, for example, than the experiential trial-and-error knowledge of craft HCI (C4) (C5) (C6) or the guidelines/heuristics of Applied Science HCI (C7) (C8) (C9) (C10) (C11) (C15) (F3) HCI Engineering principles, following the EU Conception of Engineering design knowledge, can be substantive or methodological. 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 EU HCI Engineering design problem. (C20)
The extent, to which HCI engineering principles might be realisable in practice, in the longer term, remains to be seen and demonstrated. In the meantime, craft knowledge in whatever form – models, methods, heuristics, guidelines, experience, procedures etc cannot be other than be recruited to solve HCI design problems both by researchers and practitioners (C22) (F4)
Key concepts are shown in bold on their first appearance only.
Footnotes and CitationsFootnotes
(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) ‘ Some would claim HCI theory as explanatory laws, others as design principles. Some would claim HCI theory as directly supporting HCI practice, others as indirectly providing support. Some would claim HCI theory as effectively supporting HCI practice, whilst others may claim such support as non-existent.’ (Page 10, Lines 12-17)
(C3) ‘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)
(C4) ‘Craft disciplines solve the general problems they address by practices of implementation and evaluation. Their practices are supported by knowledge typically in the form of heuristics; heuristics are implicit (as in the procedures of good practice) and informal (as in the advice provided by one craftsperson to another). Craft knowledge is acquired by practice and example, and so is experiential; it is neither explicit nor formal.’ (Page 16, Lines 4-8)
(C5) ‘…….. the (public) knowledge possessed by HCI as a craft discipline is not operational. That is to say, because it is either implicit or informal, it cannot be directly applied by those who are not associated with the generation of the heuristics or exposed to their use. If the heuristics are implicit in practice, they can be applied by others only by means of example practice. If the heuristics are informal, they can be applied only with the help of guidance from a successful practitioner (or by additional, but unvalidated, reasoning by the user).’ (Page 18, Lines 28-33)
(C6) ‘If craft knowledge is not testable, then neither is it likely to be generalisable ……To be clear, if being operational demands that (public) discipline knowledge can be directly applied by others than those who generated the knowledge, then being general demands that the knowledge be guaranteed to be appropriate in instances other than those in which it was generated. Yet, the knowledge possessed by HCI as a craft discipline applies only to those problems already addressed by its practice, that is, in the instances, in which it was generated.’ (Page 19, Lines 11 and 15-20)
(C7) ‘The discipline of science uses scientific knowledge (in the form of theories, models, laws, truth propositions, hypotheses, etc.) to support the scientific practice ……..Scientific knowledge is explicit and formal, operational, testable and generalisable. It is therefore refutable (if not proveable, Popper [1959])’. (Page 20, Lines 2-3 and 7-9)
(C8) ‘An applied science discipline is one which recruits scientific knowledge to the practice of solving its general problem – a design problem.’ (Page 20, Lines 16 and 17)
(C9) ‘ First, its science knowledge cannot be applied directly, not – as in the case of craft knowledge – because it is implicit or informal, but because the knowledge is not prescriptive; it is only explanatory and predictive. Its scope is not that of the general problem of design.’ (Page 23, Lines 20-23)
(C10) ‘Second, the guidelines based on the science knowledge, which are not predictive but prescriptive, are not defined, operationalised, tested or generalised with respect to desired effective performance. Their selection and application in any system would be a matter of heuristics (and so paradoxically of good practice).’ (Page 23, Lines 25-28)
(C11) ‘Science knowledge is explicit and formal, and so supports reasoning about the derivation of guidelines, their solution and application (although one might have to be a discipline specialist so to do).’ (Page 23, Lines 36-38)
(C12) ‘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)
(C13) ‘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)
(C14) ‘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)
(C15) ‘ Although all three conceptions address the general problem of HCI, they differ concerning the knowledge recruited to solve the problem. Craft recruits heuristics; applied science recruits theories expressed as guidelines; and engineering recruits principles.’ (Page 28, Lines 22-24)
Dowell and Long (1989)
(C16) ‘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)
(C17) ‘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)
(C18) ‘Most definitions of disciplines assume three primary characteristics: a general problem; practices, providing solutions to that problem; and knowledge, supporting those practices.’ (Page 1514, Lines 43-45)
(C19) ‘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). This theme of prescription in design is central to the thesis offered here.’ (Page 1520, Lines 1-5)
(C20) ‘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)
(C21) ‘Such a conception ….. enables the formulation of engineering principles which embody and instantiate those concepts. ( Page 1520, Line 46 and Page 1521, Line 1)
(C22) ‘The extent to which HF engineering principles might be realiseable 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)