Ten years ago, Thaler and Sunstein introduced the notion of nudging to talk about how subtle changes in the 'choice architecture' can alter people's behaviors in predictable ways. This idea was eagerly adopted in HCI and applied in multiple contexts, including health, sustainability and privacy. Despite this, we still lack an understanding of how to design effective technology-mediated nudges. In this paper we present a systematic review of the use of nudging in HCI research with the goal of laying out the design space of technology-mediated nudging - the why (i.e., which cognitive biases do nudges combat) and the how (i.e., what exact mechanisms do nudges employ to incur behavior change). All in all, we found 23 distinct mechanisms of nudging, grouped in 6 categories, and leveraging 15 different cognitive biases. We present these as a framework for technology-mediated nudging, and discuss the factors shaping nudges' effectiveness and their ethical implications.

https://dl.acm.org/doi/pdf/10.1145/3290605.3300733

23 Ways to Nudge: A Review of Technology-Mediated Nudging in Human-Computer Interaction

Persuasive technologies aim to influence user's behaviors. In order to be effective, many of the persuasive technologies developed so far relies on user's motivation and ability, which is highly variable and often the reason behind the failure of such technology. In this paper, we present the concept of Mindless Computing, which is a new approach to persuasive technology design. Mindless Computing leverages theories and concepts from psychology and behavioral economics into the design of technologies for behavior change. We show through a systematic review that most of the current persuasive technologies do not utilize the fast and automatic mental processes for behavioral change and there is an opportunity for persuasive technology designers to develop systems that are less reliant on user's motivation and ability. We describe two examples of mindless technologies and present pilot studies with encouraging results. Finally, we discuss design guidelines and considerations for developing this type of persuasive technology.

Mindless computing: designing technologies to subtly influence behavior

We propose a definition of symbiotic interaction that is informed by current developments in computing. We clearly distinguish this definition from previous ones and from selected paradigms that address the human-computer relationship. The definition is also informed by a variety of human-centered frameworks in human-computer interaction, including embodied interactions, situationist frameworks, and participatory and work-oriented design perspectives. Symbiotic interactions can be achieved by combining computation, sensing technology, and interaction design to realize deep perception, awareness, and understanding between humans and computers. Important aspects to implement are transparency, reciprocity, and collaborative use of resources for both computers and humans. The symbiotic relationship is also characterized by goals and agency independence of humans and computers. The definition sets the premise to discuss in a critical way future research agendas for symbiotic interactions that are sensitive to human-centered values.

Symbiotic Interaction: A Critical Definition and Comparison to other Human-Computer Paradigms

An interactive and low-cost full body rehabilitation framework based on 3D immersive serious games.

Emotional and cognitive influences in air traffic controller tasks: An investigation using a virtual environment?

The capability of machines to covertly persuade humans is both exciting and ethically concerning. In the present study we aim to bring subliminal masked stimulus paradigms to realistic environments, through Virtual Environments. The goal is to test if such paradigms are applicable to realistic setups while identifying the major challenges when doing so. We designed a study in which the user performed a realistic selection task in a virtual kitchen. For trials below one-second reaction time, we report significant effect of subliminal cues on the selection behavior. We conclude the study with a discussion of the challenges of bringing subliminal cueing paradigms to realistic HCI setups. Ethical concerns when designing covertly persuasive systems are discussed as well.

Covert Persuasive Technologies: Bringing Subliminal Cues to Human-Computer Interaction

The performance of current graphics engines makes it possible to incorporate subliminal cues within virtual environments VEs, providing an additional way of communication, fully integrated with the exploration of a virtual scene. In order to advance the application of subliminal information in this area, it is necessary to explore in the psychological literature how techniques previously reported as rendering information subliminal can be successfully implemented in VEs. Previous literature has also described the effects of subliminal cues as quantitatively modest, which raises the issue of their inclusion in practical tasks. We used a 3D rendering engine Unity3D to implement a masking paradigm within the context of a realistic scene and a familiar kitchen environment. We report significant effects of subliminal cueing on the selection of objects in a virtual scene, demonstrating the feasibility of subliminal cueing in VEs. Furthermore, we show that multiple iterations of masked objects within a trial, as well as the speeding of selection choices, can substantially reinforce the impact of subliminal cues. This is consistent with previous findings suggesting that the effect of subliminal stimuli fades rapidly. We conclude by proposing, as part of further work, possible mechanisms for the inclusion of subliminal cueing in intelligent interfaces to maximize their effects.

/pdf/subliminal-cueing-of-selection-behavior-in-a-virtual-33vfdnkcpf.pdf

Subliminal cueing of selection behavior in a virtual environment

Subliminal stimuli can affect perception, decision-making, and action without being accessible to conscious awareness. Most evidence supporting this notion has been obtained in highly controlled laboratory conditions. Hence, its generalization to more realistic and ecologically valid contexts is unclear. Here, we investigate the impact of subliminal cues in an immersive navigation task using the so-called eXperience Induction Machine XIM, a human accessible mixed-reality system. Subjects were asked to navigate through a maze at high speed. At irregular intervals, one group of subjects was exposed to subliminal aversive stimuli using the masking paradigm. We hypothesized that these stimuli would bias decision-making. Indeed, our results confirm this hypothesis and indicate that a subliminal channel of interaction exists between the user and the XIM. These results are relevant in our understanding of the bandwidth of communication that can be established between humans and their physical and social environment, thus opening up to new and powerful methods to interface humans and artefacts.

Hielke Prins

Papers

Covert Persuasive Technologies: Bringing Subliminal Cues to Human-Computer Interaction

Subliminal cueing of selection behavior in a virtual environment

Subliminal response priming in mixed reality: The ecological validity of a classic paradigm of perception