This thesis reports an investigation to develop new understanding of pleasant experiences resulting from human-product interaction, which is then used to inform the development of a process and tools to support designers. The key argument of this research is that pleasant experiences can be designed. The thesis starts by providing a foundation of user experience. A new framework of user experience is proposed based on the analysis and synthesis of previous literature (Chapter 1).
The interest then shifts from user experience to characterising pleasant experiences. Four empirical studies are presented focusing on aspects such as experiences with great products and the role of positive emotions in those experiences. The first study, investigating how users experience great products, identifies and characterises pragmatic and significant experiences (Chapter 2). Great products were studied as people understood and experienced them. In the second study, a set of twenty-five positive emotions are ranked by users and designers to understand what emotions they prefer to experience and elicit through their designs (Chapter 3). Highly-preferred emotions by users were: satisfaction, inspiration, confidence, joy, amusement and relaxed. Highly-preferred emotions by designers were: curiosity, joy, surprise, confidence, inspiration, fascination, satisfaction, and pride. In the third study, the twenty-five positive emotions are researched to understand their differences in pleasantness and arousal (Chapter 4). Three levels of arousal and pleasantness of emotions were identified and these are: exciting, neutral and calm emotions, and pleasant, quite pleasant, and very pleasant emotions. In the fourth study, anticipation, confidence, inspiration, and sympathy are investigated in depth to create rich profiles of the emotions (Chapter 5). The profiles focus on the triggers, appraisal structures, thought-action tendencies, and thematic appraisals of the emotions.
Building on the understanding of pleasant experiences emerged from the re- search above, the thesis then presents evaluative research. In the fifth study, a design process and tools to support designers in the elicitation of pleasant experiences are proposed and tested. The process shows how emotional profiles can be used by designers as a means to create pleasant experiences through emotions (Chapter 6).