access_time 26 de novembro de 2018 às 15:30 até 26 de novembro de 2018 às 16:30
place IST Alameda, Room 0.17 Informática II Building
Behavior change technologies, such as physical activity trackers focusing on self-regulation techniques, face two major challenges: a) they rely on people’s motivation to constantly track and examine their behavioral data, and b) they assume people’s ability to deduce patterns and identify opportunities for action. An alternative approach would be to nudge individuals towards healthy choices right when they face a decision (e.g., “should I take the stairs or the elevator?”), thus relying less on people’s ability and motivation to regulate their behaviors. This dissertation aims to explore the design space of computer-mediated nudging technologies in the context of health behaviors, and develop a software platform for the rapid prototyping, deployment and evaluation of computer-mediated nudges.With most of current persuasive technologies enacting with conscious awareness thus holding an ongoing risk of reactance (i.e. users rejecting interventions to preserve autonomy), our first inquiry focused on the use of technology to target nonconscious processes to drive behavior change. For this purpose, we investigated how subtle influences falling outside conscious awareness could instinctively prompt users to change behavior. In this dissertation, we outline the design and development of Subly, an open-source Chrome browser plugin that subliminally primes behavioral concepts through slight emphasis on words and phrases as people browse the Internet. Subly was devised as an open-source web research tool that allows third-party researchers to design and validate their own subliminal behavior change intervention, making a contribution to the exploration of subliminal priming as a behavior change strategy. We present three studies with Subly: one that identifies the threshold of subliminal perception and one that demonstrates the efficacy of Subly in a picture-selection task. While both studies revealed promising results in consonant with prior evidence of subliminal stimuli, an inquiry into it effectiveness motivating behavior change was overlooked and it feasibility was not measured in a non-controlled setting. Motivated by this, we conducted a third inquiry to assess the feasibility of Subly in the wild, where 12 participants were exposed to subliminal cues to motivate water intake while they browsed the web. We evaluated the effectiveness of two types of stimuli: positive and neutral, and explored their influence on different hydration levels. Our results were insufficient to provide significant effects yet, they support prior work indicating that when semi deprived people infer the goal more readily than participants with low deprivation. Our inquiries allowed us to observe that subliminal priming, however, is strongly influenced by individual’s selective attention to process the stimulus unconsciously. This circumstance is shape not only by the individual, but also by the cues provided, existing the possibility that the user is not exposed to a nudge when he would benefit from it (i.e. the user may not be using the browser). These constrains led to a second project and current ongoing work. Behavior economics has identified a number of heuristics and cognitive biases - errors in thinking that deviate judgments from rational decision-making – that affect decision-making and human behavior. However, while they play a key role in how we make judgments, they are often neglected during the design of persuasive technologies and there is no knowledge on how they have been used to encourage change. In a first attempt to understand how technology can be designed to influence choice, we looked at the heuristics behind the decision-making process and used this knowledge to systematically review published empirical work in the HCI field. We reviewed 113 publications from top HCI conferences (i.e. CHI, CSCW, Ubicomp, DIS, UIST, IUI and MobileHCI). The contribution to knowledge offered by this review centers on a design pattern toolkit for the design of nudging technology that gathers behavior change techniques from a range of disciplines and supports researchers in a unified way. The toolkit is a collection of seven design strategies: Facilitate, Dissuade, Pressure, Confront, Scare, Fool and Reinforce, framed around the why (i.e. why the heuristic used can bias behavior), the what (i.e. what heuristics can be tackled to nudge) and the how (i.e. in which ways the interface can be designed to tap into specific heuristics). Our future work aims to a) lay out a set of design guidelines for the development of a card-based design tool, able to assist and provide structure to the design process, and b) the development of a web platform that supports the design of nudges in the context of health behaviors. With wearables devices being the most mobile feedback display available, we will focus our attention on smartwatches interfaces. To develop the platform, we will first conduct a set of empirical studies to examine the design and effectiveness of different techniques uncovered in the review and use the applications developed as the foundation to build the platform.
local_offer Prova de CAT
person Candidato: Ana Karina Caldeira Caraban
supervisor_account Orientador 1: Prof. Daniel Jorge Viegas Gonçalves
supervisor_account Orientador 2: Prof. Pedro Filipe Pereira Campos
supervisor_account Orientador 3: Prof. Evangelos Karapanos