Persuasion can be defined as an active attempt by a person to change the behavior and attitudes of others. The purposive attempt to influence one’s behavior can originate from different areas, and people who are able to do so are often referred to as influencers. Social media platforms such as Instagram or YouTube have become crucial platforms for influencers who generate their income by recommending products and services to their followers, including cosmetics, multimedia articles or clothing. Studies indicate that influencers actively try to persuade the viewer to adopt specific desirable behavior by strategically altering their displayed behavior on social media. Such strategies have mainly been explored in the context of beauty products, where lack of expertise and misinformation might have few negative consequences. Less is known about strategies used in a health-sensitive context, such as nutritional supplements. This research addresses this gap and aims to understand persuasive techniques used by health professionals on YouTube to promote the use of protein supplements. This study is based on an interpretive paradigm using interpretive grounded theory to analyze 60 YouTube videos. We developed a three-step model of persuasion for YouTube videos consisting of the steps: reaching the message, staying on the message, and performing the action that the persuader desires. Our analysis resulted in five core themes that contributed to the persuasiveness of the analyzed YouTube videos. These themes included: Quality, curiosity, engagement, concretization, and genuineness. We conclude the paper with reflections on our model’s theoretical and practical implications.@en

The consumption of a meal is not just a bodily requirement but can also carry significant symbolic meaning. Solo dining is often contrasted to a shared eating experience and portrayed as an inferior way of eating a meal due to lacking essential social and normative qualities. Human-computer interaction research increasingly explores different ways of enhancing the solo dining experience. However, a focus seems to be on recreating aspects essential to the shared eating experience, such as a dining companion being present, rather than trying to enhance aspects that solo diners enjoy and, therefore, contribute to a reverie in eating. Based on earlier research findings, we developed a design concept that includes sound and visual elements supporting the multi-sensory eating experience and encouraging the user to concentrate on the food rather than seeking distraction. The formative usability evaluation results indicate that the proposed design needs further refinement to evoke the anticipated effect. @en

To improve people's lives, human-computer interaction researchers are increasingly designing technological solutions based on behavior change theory, such as social comparison theory (SCT). However, how researchers operationalize such a theory as a design remains largely unclear. One way to clarify this methodological step is to clearly state which functional elements of a design are aimed at operationalizing a specific behavior change theory construct to evaluate if such aims were successful. In this article, we investigate how the operationalization of functional elements of theories and designs can be more easily conveyed. First, we present a scoping review of the literature to determine the state of operationalizations of SCT as behavior change designs. Second, we introduce a new tool to facilitate the operationalization process. We term the tool blueprints. A blueprint explicates essential functional elements of a behavior change theory by describing it in relation to necessary and sufficient building blocks incorporated in a design. We describe the process of developing a blueprint for SCT. Last, we illustrate how the blueprint can be used during the design refinement and reflection process.@en

Overweight, obesity and cardiometabolic diseases are major global health concerns. Lifestyle factors, including diet, have been acknowledged to play a key role in the solution of these health risks. However, as shown by numerous studies, and in clinical practice, it is extremely challenging to quantify dietary behaviors as well as influencing them via dietary interventions. As shown by the limited success of ‘one-size-fits-all’ nutritional campaigns catered to an entire population or subpopulation, the need for more personalized coaching approaches is evident. New technology-based innovations provide opportunities to further improve the accuracy of dietary assessment and develop approaches to coach individuals towards healthier dietary behaviors. Pride & Prejudice (P&P) is a unique multi-disciplinary consortium consisting of researchers in life, nutrition, ICT, design, behavioral and social sciences from all four Dutch Universities of Technology. P&P focuses on the development and integration of innovative technological techniques such as artificial intelligence (AI), machine learning, conversational agents, behavior change theory and personalized coaching to improve current practices and establish lasting dietary behavior change.@en

Commensality, the act of eating together, is commonly associated with many benefits. Dining solo, in contrast, is frequently connected to adverse effects on a person. There is a growing interest in human-computer interaction (HCI) and design in how innovations can enhance eating experiences by, for example, facilitating commensality. The steadily growing number of people eating alone and the associated risks beg the question of how HCI and design could contribute to and improve the solo dining experience and whether or not mimicking or facilitating commensality is what solo diners want. This two-phased study reports on the context exploration of the multimodal solitary dining experience. In the first phase, we scoped the literature describing the benefits and drawbacks of solo dining and commensality. For the second phase, a digital food diary was developed and completed by six solo diners to collect further insights and user requirements. Photos and annotations collected as part of the food diary were analyzed using content analysis. The results indicate several advantages of eating alone, including feeling relaxed, perceiving solo dining as a moment of self-pampering, and appreciating the cooking experience. Overall, it seems that solo dining is not merely a lack of commensality, but a unique experience in and of itself, where people seem to strive towards finding reverie in eating.@en

Theories from psychology or the social sciences are commonly used as a starting point when designing persuasive technologies that aim to evoke a specific behavior change. Ideally, using these theories would (1) help guide the design of the persuasive technology and (2) help evaluate and inform the theory. In this paper, we focused on the first aspect and looked at how papers report on how a theory guided the design of persuasive technology. We performed a scoping review focused on the operationalization of social comparison theory as part of persuasive design. We chose social comparison due to its ubiquitous use in persuasive design as well as its potential positive or negative influence on the user. The former requires careful consideration in a persuasive design prototype. We focused on the proceedings of the Persuasive Technology conference from 2006 to 2020 to gain an understanding of the use of social comparison theory as part of persuasive design. Twelve studies met our inclusion criteria. Explanations of how the theory guides design decisions leading to the final operationalization were sparse. We suggest that conducting manipulation checks and using a systematic approach to reporting design decisions including the potential grounding of design elements in theory could highlight and clarify theoretical insights, and could increase our understanding of how social comparison—and behavior change theory in general—could be efficiently operationalized in persuasive technologies.@en