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.

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For health and environmental reasons, humanity should reduce the consumption of animal-based products, whereas vegetable consumption should be increased. We created stimuli (drawings with texts) that may be able to increase or decrease the purchasing of mushrooms, cheese, and meat. During the design process, we identified four aspect categories (sensory, health, environment, moral) and we generated positive and negative examples for all products. In Study 1 we determined the familiarity, credibility and relevance of each aspect and measured emotional responses to them. In Study 2, we investigated to what extent four aspects combined in an infographic on a poster lessened or strengthened the emotional responses, purchase intention, and tendency to adapt behavior for the three products. Regression analyses showed that the emotional responses to the posters were well predicted by the responses to the product aspects. Purchase intentions were mainly affected by negative affect, while positive and negative affect seemed equally important for people’s intention to change behavior.

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The movement of food may suggest the food is very fresh but may also indicate the source of food is still alive. In this study, we explore the responses that different kinds of food movements can evoke among consumers. In an online study, we presented participants with 14 videos in which a food product changed shape or moved, before or while being eaten. They rated their emotional responses to the food (disgust, fear, fascination), their tendency to empathize with the beings in the video, characteristics of the movements, and how they experienced the food. Most foods that moved in the videos elicited more disgust than expected for those food items. Many product aspects that elicited disgust also evoked empathy, while fascination showed opposite patterns. Products elicited empathy and disgust when they seemed to be alive and potentially harmful, and their movements were twitchy. Participants empathized mainly with larger animals, while disgust was particularly high for smaller animals like maggots in cheese and crawling coconut worms. People became fascinated with foods they found safe, nutritious, and that looked attractive, while the food movements were subtle and looked natural with the food. These results showed that the movements of foods that appeared to be alive were different from what was considered natural for the food, and so they also evoked different emotional responses.@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

Changing a specific health behaviour can be highly com- plex and is often influenced by many personal, social, and environmental factors. Therefore, interventions that aim at behaviour change cannot be one-size-fits-all solutions, and no behaviour change technique is effective for everyone. One potential solution could be to support individuals in finding interventions through self-experimentation. This research explored the requirements for an explorative self- experimentation intervention and developed tools that sup- port users in the process, complementing developments in quantitative self-experimentation. Based on a research through design approach, we developed three different prototypes for supporting a change in health-related behaviour, which were used and evaluated by fourteen par- ticipants over a four-week period. A thematic analysis of interviews with participants led to seven themes, which can be used as a starting point when designing for explorative self-experimentation.@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

Disgust is commonly understood as an emotion of aversion. However, people seem to eat certain food items not despite containing disgust eliciting features but because of them. In this paper, we introduce the term aesthetic disgust to capture this phenomenon. We outline in our manuscript how designers use different techniques to stage the food experience and facilitate aesthetic disgust, which can be understood as more than just a pleasurable experience. We outline twelve staging techniques used in the context of food design to facilitate a distancing or embracing effect regarding the disgust eliciting features. Three food examples illustrate how these different techniques can be combined and applied in design practice.@en

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

Stroke causes damage to the brain, often resulting in weakness or paralysis on one side of the body. Everyday objects such as smartphones can play an im-portant role after a stroke facilitating participation in daily activities. However, commercial smartphones can be challenging to use, and people with stroke of-ten adjust their behavior to minimize the affected arm and hand use. This study explores how an object attached to a smartphone could evoke behavior change and contribute to the initiation of use of the affected arm. As part of a design workshop, different ideas were envisioned to promote the use initiation of the affected side of the body. Two high-fidelity smartphone accessories were devel-oped and tested with four people with chronic, mild stroke impairments based on the results. The initiation of use observed during the formative usability test seems to be evoked by the learned behavior patterns rather than the design prototypes.@en

Commercial food packages may contain multiple messages. Packaging designers try to integrate all messages into a coherent design. Designers may use text, images or stylistic features, but these mediums may differ in their suitability to communicate specific product benefits. To evaluate the usefulness and effectiveness of these three mediums, we not only obtained consumer evaluations of packaging designs, but we also monitored the designer's experience during the design process. For three products (orange juice, muesli bar, plain yogurt) we created three consistent packaging designs communicating a single benefit through all three mediums, which was either a [1] health, [2] environmental, or [3] production, sensory or social claim. Subsequently, we developed inconsistent packages communicating three different messages through the three mediums. In an online survey, each of the 18 package variants was evaluated by 59–92 participants. Dummy regression analysis suggested that verbal claims had positive effects in communicating healthiness and environmental friendliness but elicited a negative tendency for sensory properties. The images we used indicated a positive effect for communicating worker conditions, but a negative effect for healthiness. Our stylistic elements suggested a positive effect for sensory appeal, but tended to have negative effects for environmental aspects. As regards designer dilemmas, we noticed that some images (e.g., in the medical domain) required specific graphic styles to make them acceptable for commercial use. Our findings suggest that consumers can handle multiple packaging messages, but finding an optimal configuration remains a design challenge.

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With one-person households being increasingly common and Covid-19 lockdown policies forcing people to stay home, remote dining has become common practice for many, who take it as an opportunity to connect with others in times of loneliness. Sharing meals online, also known as digital commensality, is a rich form of interaction, where people leverage technology to achieve a sense of connectedness and belonging while eating. In this paper, we look at digital commensality and we explore its inherent playful potential with the aim to inspire the design of engaging technologies that can support, enhance and augment this form of interaction. For this, we used a situated play design approach to document and analyze the behavior of 36 people (including pairs of friends and strangers) sharing meals online. Our analysis surfaced a set of play potentials of remote dining - i.e., playful things people already do and enjoy spontaneously while sharing meals online. We present those play potentials as inspirational material: they can motivate and enrich the design of future digital commensality technologies by responding to people's desire for playful and social interaction with, through, and around food.@en

The consumption of a solo meal is often subject to negative associations. Studies indicate that solo diners use information and communication technology (ICT) devices such as smartphones, to mitigate negative experiences such as boredom and loneliness, especially when dining in a public context. However, we know less about the motivation to use such devices and consequent meal experiences in a private context. For this exploratory qualitative study, we asked participants to fill out a cultural probe kit to capture their dining experience and use of ICT devices over a period of seven days. Once completed, the content was discussed with participants during a semi-structured interview. Data was analyzed using thematic analysis in a deductive and inductive form leading to four themes: (1) The experience of eating with others; (2) The use of electronic devices while eating; (3) The meaning of food; and (4) Relaxing features and influences. Participants indicated that eating alone can be a pleasurable experience that people enjoy and perceive as relaxing. ICT devices were named to play an essential part in the dining experience. The entertainment that devices provide can mitigate feelings of loneliness and uncomfortable silence when eating by oneself. We reflect on the findings and point out potential design avenues for future studies.@en

Obesity has been pointed out as one of the main current health risks leading to calls for a so-called “war on obesity”. As we show in this paper, activities that attempt to counter obesity by persuading people to adjust a specific behavior often employ a pedagogy of regret and disgust. Nowadays, however, public healthcare campaigns that aim to tackle obesity have often replaced or augmented the explicit negative depictions of obesity and/or excessive food intake with the positive promotion of healthy food items. In this paper, we draw on a phenomenological perspective on disgust to highlight that food-related disgust is connected to the character and behavior of a perceived individual even in the context of promoting healthy food items. We argue that the focus on “making the healthy food choice the easy choice” might be an important step towards the de-stigmatization of people that are affected by obesity. However, so we suggest, this focus threatens to bring back an image of individuals affected by obesity as disgusting “through the backdoor”. It does so not by portraying bodies with overweight as disgusting, but instead by implying that lifestyle choices, character and habits of people that are affected by obesity are markers of a lack of control. We argue that the close relationship between disgust and the perception of self-control in the context of obesity should be taken into consideration in the context of assessing the implications of new health promotion strategies to minimize the risk of stigmatizing people.@en

Although governments have implemented regulations to inform consumers on important product properties and protect consumers from deceptive information, empirical research on how consumers perceive, interpret and experience food packages have shown frequently that consumers may be misled by how information is presented and packages are designed. While communication in some domains is strictly regulated (health), claims in other domains are largely free (nature) and do not require substantiation. Subtleties in wording, image use and image style may affect the impressions consumers form. To support consumer decision making, legislators should not only provide rules and regulations that are formally correct, but also consider the effects a message and the way it is communicated (e.g., content, typeface, size, use of images, stylistic features) may have on buyers. While it may be unclear how best to support desirable behaviours, companies that take social responsibility can build on our work to develop their strategy.

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Disgust is a strong emotion of aversion. In the context of food, it is often referred to as a guardian of the mouth, preventing close contact with pathogens and the accidental consumption of poisons. However, disgust can also create a certain level of attraction and be part of positive experiences, even in the context of food. In this article, we discuss different ways of using disgust to influence eating behaviour and contribute to healthier food consumption. We outline ten different bridging concepts accompanied by various design exemplars on how to use disgust in the context of critical food design. In addition, we present four different lenses that can help to refine the design concepts.@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

An increasing number of people tend to eat alone due to social changes and an altered attitude towards cooking and eating practices. Anecdotal reports indicate that solo diners tend to use information and communication technology devices, for example, the smartphone, as part of the eating experience. While lab studies suggest that the devices contribute to an increased high-calorie food intake and decreased feeling of satiety, these studies disregard the everyday experience and motivation of solo diners. We conducted an exploratory study to investigate how solo diners use digital devices as part of their daily eating experience. Semi-structured interviews with solo diners (N =12) were analyzed using thematic analysis in an inductive approach leading to six themes. The themes focus on (1) the perception of a meal; (2) the experience of a solo diner; (3) the purpose of using an information and communication technology device; (4) the perceived influence of the devices; (5) factors decreasing and increasing the use; (6) and the potential to promote healthier food consumption. Our results indicate that the use of digital devices while eating alone can lead to distraction, being unaware of the food texture and the amount that is eaten. The devices can also induce a positive influence by providing entertainment and mitigating negative emotions like loneliness and boredom. The devices have the potential to contribute to healthy eating practices by providing education and by influencing the speed of eating through elements of sound. Although the use of devices might negatively affect eating behavior, their ubiquitous presence also offers the opportunity to reach specific, vulnerable populations. @en