| The aim of this dissertation is to study and assess comfort, pleasure and cognitive engineering for relevance in engineering design processes, working towards finding an integrated theoretical structure. From this overall aim, operative aims and research questions were derived and pursued with the support of literature studies and analysis of five empirical studies. The operative aims are: establish the levels of scientific knowledge (in terms of development potential and feasibility); test the levels of development in practice of theoretical structures, data collection methods and representation formats; and, apply activity theory to attempt compatibilizing the three theoretical structures (broken down into subconcepts, operatives and measurable variables). Conclusions and conclusive remarks are delivered, springing from the analyses made. The results of the assessments of model validity and maturity showed that universal design methods in comfort, pleasure and cognitive engineering, for direct application by engineering design, are presently not available, with an exception found for thermal comfort. Predictability concerning seat comfort, cognitive engineering and pleasure with products has not yet been achieved, but it is deemed feasible for some of their sub-areas: modelling physical discomfort in sitting, modelling pleasurable product properties for cultural sub-groups and predicting patterns of the impact of change on joint cognitive systems. Other sub-areas are not considered worthwhile pursuing for attaining engineering systematization, since their predictability is not deemed attainable. This situation hence precludes the development of a complete integrated comfort, pleasure and cognitive engineering design method for unaided application by engineering design. In these areas, design problems are thus better tackled using a combined process of research and design, which recurs to the existing theoretical structures but also to context based research intended to fill in the gaps of theory. A moderate level of compatibility between the theoretical structures of comfort, pleasure and cognitive engineering was attained. While pleasure pursues in practice the goal of adding gains, comfort and cognitive engineering struggle in practice with relieving pain and minimizing loss. The psychological human aspect is common to all three areas, although it is not pursued in practice in comfort, nor does cognitive engineering pursue in practice the psychological aspect of emotions. Partial commonalities were found between comfort and pleasure (in what concerns physical aspects) and between cognitive engineering and pleasure (in what concerns psychological aspects) at the level of subconcepts. A common underlying activity structure of activity-goal-user-artefact was demonstrated for the empirical studies dealing with comfort and cognitive engineering. This showed, for both areas, that deriving measurable variables and identifying operatives could be done from the operation level of activity theory, once the elements relevant to the design problem are classified according to the activity-user-goal-artefact categories. Activity theory also enabled structuring and organizing a common research-design process underlying the conduction of specific design studies in comfort and cognitive engineering. This process is also suggested as applicable for designing Human Factors and Ergonomics quality wherever theory gaps are found. |
