This study investigates the effect of personalising a product's appearance on the emotional bond with a product. We present a conceptual model for the relationships between the effort invested during the process of product personalisation, the degree of self-expression, and the degree of emotional bonding. Data from a questionnaire study in which respondents (n=149) filled out questions concerning their (non-) personalised bicycle support our expectations. By personalising the product's appearance, a person invests effort in the product. Our findings show that the amount of effort invested has a direct effect (as a result of the extended period of time spent with the product) and an indirect effect (via the personalised product's self-expressive value) on the strength of the emotional bond with the product. The paper concludes by discussing the implications of these findings for product designers.

Understanding how consumers perceive products based on their appearance is of great importance to designers. In this article, we explore the level of novelty of a product appearance as a general design guideline to evoke positive associations about the product's performance quality. Novelty implies the deviation in a product appearance from the current design state. Based on the literature, we theorise that consumers associate products with a novel appearance with technological advancement and thus with a greater performance quality. Data from two studies in which participants were asked to evaluate washing machines and single-lens reflex cameras support our expectations that the level of novelty of a product appearance positively affects the perceived performance quality of the product.

Many products are disposed of before they have reached the end of their functional life. New technological developments and trends in fashion seem to accelerate consumers' replacement of products. From an environmental perspective, such early replacement is undesirable. In this paper, we emphasize that product replacement is not only based on rational decision making. Emotional, functional, social, epistemic and conditional values can influence the value trade-offs that consumers make during the decision to either retain an owned product or replace it with a new one. Several strategies are discussed that can increase the owned product's values and stimulate retention via product attachment, sustaining aesthetic value, stimulating product care and maintenance, and enabling upgradeability.

Feedback systems with direct feedback have shown to be effective in stimulating households to change their energy consumption levels. This research is one of the first to explore the use of apps to influence household energy use. Compared to dedicated in-home displays, smartphone/tablet apps provide a low-cost and simple design solution for making energy feedback available. This research consisted of three studies conducted with different samples within a selection of households where a smart meter was installed as part of the smart meter implementation program in the Netherlands. First, for a period of 16 months, electricity and gas consumption levels were measured for a large sample of households (n = 519) divided into an application user group and a reference group. Second, questionnaires (n = 270) provided insight in how people used the applications and to what extent the applications increased households’ insight in their energy consumption and stimulated behavior changes. Third, interviews (n = 12) were held to obtain more in-depth insight. In the sample with measured energy consumption, we did not find a significant reduction in electricity and gas consumption during this research. Yet in the questionnaires, the application users reported more energy awareness and indicated to have made more investments and changes in their behavior than the reference group. Most app users started using the first app they found and did not explore the other options. The interview results indicate that, after an initial learning period, the app was used to monitor the electricity and gas consumption levels, rather than to lower them. In line with other research into feedback, the interview results suggest that the apps could be more effective with information that is more actionable and meaningful with respect to one’s own specific situation and goals for the household. Further exploration is recommended with respect to how the design of such apps can encourage a wide audience not only to monitor their consumption, but also guide them in taking action to change their consumption levels.