There is more and more need to use participatory design, usability studies and user studies in product design concerning user interfaces, for example. Each product should be seen as a component in a individual-technology-task-environment-organisation system. The system approach can hence be recommended as an applicable basis for better understanding the users’ needs in product development. It will help to build the increasingly necessary bridges between customer attributes and engineering charateristics as far as product creation is concerned. This study aimed to provide linking attributes and characteristics. The specific objectives of this study were achieved. The achievements are numbered in the same order as they were introduced in chapter 3:
Potential product evaluation methods were chosen on the basis of the literature and applied to various cases. The emphasis was on simple methods that are easily applicable to gerontechnology and probably also to other contexts.
Using these methods, the opinions of end-users, especially the elderly, were easily and quickly incorporated into the judgement process done by the designer. The process was concrete, thanks to the simulation of the products and the tasks to be done; this might be an advantage compared to the recent trends towards more abstract virtual models. Most of the procedures enabled a real visual contact and tangible communication between the product and the subjects. With the methods used, potential users, as future customers, are involved in the product development process in a reliable and systematic way. And their experiences of both performance and preference are elicited cheaply and can be utilised in the development process.
This study was able to indicate which method is more appropriate or relevant in each phase of design, as shown in Table 8.
The procedures used gave statistically significant results of the cases under consideration. The procedures can be considered consistent enough. There is no one superior statistical method to be used. Different statistical methods can be and were used in the different cases. The usability engineering approach with user trials can constitute the basis of the product development cycle for companies that consider ease of use as a major issue. The usability test served as an applicable method to set the usability criteria in order to test whether the new design achieves it objectives.
The EEE procedures – at least in a research context – enable designs to be evaluated systematically within the context of strict budgets, limited time and participative trials involving end-users. Evidence was gathered for methodological recommendations, which were made in the course of the EEE procedures described in chapter 6.1. Ergonomic input should be systematic across product development. A combination of methodological elements that will make possible both unit measurement, subjective evaluation and expert evaluation can be recommended.
This study gave some examples of evaluative results. It ranked and rated single criteria or properties, especially ergonomic ones, in various technologies, which were either traditional products (chairs, task-surfaces) or ICT products (telephone, videoconferencing system).
End-users, whether employers or consumers, utilise various technological products at work and at home. Relevant usability evaluation is in the interests of both end-users and manufacturers. A shared tool for both sides is participative design, which means systematic collaboration in trials and decision-making. Experimental ergonomic evaluation – EEE – combines the scientific literature, the application of methodological innovations, such as computer-aided conjoint analysis, research expertise and experimenting with people as users and, finally, usability engineering with objective and subjective metrics and statistical analysis of the significance of the results. The experiments with participatory users and real or simulated tasks highlight the importance of the field context and validity.
Any real design always implies multi-criteria decisions with trade-offs. EEE has been shown to be a feasible and reliable tool in a wide range of cases, and it has diverse possibilities in user-centred design in general. Based on the experiences gained here, EEE can be recommended for use as routine tests in product development within industrial companies. One of the most crucial starting points of EEE turned out to be the successful communication of product concepts, prototypes and criteria. This helped to optimise the criteria and the ranking and rating properties for both low- or high-tech products. Elderly users are in need of new products. On the other hand, they were seen as useful pilot group as far as the pertinent development of EEE was concerned. The elderly also demonstrated the importance of tailoring the whole ergonomic developmental sequence from exact objectives, such as anthropometirc characteristics, to more subjective – though measurable – perceived attributes.