Exploring the Design of Nudging in Persuasive Technologies { Improving Sleep Hygiene Hung-Chiao Chen Master's Thesis, 30 ECTS Master's Programme in Cognitive Science, 120 ECTS Spring 2021 Supervisor: Helena Lindgren, Esteban Guerrero Rosero, Lo¨ısVanh´ee Acknowledgement Special thanks to Lo¨ısVanh´ee,Esteban Guerrero Rosero and Helena Lindgren for leading me through this incredible learning experience. The journey would not have been as fruitful if it was not for the help and support from them. I also want to thank all the participants that took part in this study. They have provided me the most valuable insights and encouragement that made this thesis possible. 2 Abstract Research on persuasive technologies for promoting healthy behaviours has been surging in recent years, but these technologies have the risk of being perceived as undesirable meddling. The current study puts forward a non-coercive and libertarian paternalistic alternative { the nudge theory. The foundation of the nudge theory is informed by the dual processing theory and can be categorized in two types { Type 1 nudging and Type 2 nudging. As design tools, two Type 1 nudging methods: default setting and manipulation of accessibility; and four Type 2 nudging methods: reminders, prompts, framing and pre- commitment strategies were selected to be featured. Sleep was chosen as the use case for this study, for it is associated with a number of non-communicable diseases yet considerably few studies of persuasive technology are about sleep. Better sleep hygiene is a significant means to improve sleep, therefore used as the design goal. The current study explores possible solutions for persuasive technologies for improving sleep hygiene, and better understand the design potentials and the persuasive characteristics of different types and methods of nudging. The research methodology is informed by scenario-based design. Five (four male and one female) academic professionals with backgrounds in interaction design, human-computer interaction, artificial intelligence and robotics took part in the study. Seven scenarios and thirteen prototypes were created to illustrate the situations and present the possible solutions. Results also showed that Type 1 nudging is considered more convenient and effective. However, the sense of control is better preserved in Type 2 nudging. In regard to nudging methods, default setting is considered as the most effective method under the condition of goal-alignment, but prone to error. Manipulation of accessibility should be designed so that the navigation is intuitive and the integrity of availability should not be damaged. Timing is the most prominent factor for reminders, and the influence of reminders could be reinforced by prioritizing and cross-platform availability. The presence of prompts could be emphasized by purposeful placement, and appropriateness should be considered. The perception of framing is highly subjective, therefore it should be user-tailored and context-aware. The effects of pre- commitment strategies are able to access higher-level motivation, but should be reinforced with other methods. To summarize the design principles, when designing nudges in persuasive technologies, the following factors should be considered: goal alignment, intuitiveness, context awareness, availability and accessing motivation. Keywords: persuasive technology, the nudge theory, Type 1 nudging, Type 2 nudging, default set- ting, manipulation of accessibility, reminders, prompts, framing, pre-commitment strategies, sleep, sleep hygiene, scenario-based design 3 Sammanfattning Forskning inom temat persuasive teknologi f¨orh¨alsoinriktade beteenden har ¨okat under den senaste tiden. Dock kan s˚adanateknologier oftast uppfattas som en o¨onskad inblandning i m¨anniskors privata liv. Denna studie f¨oresl˚arett otvingade och libertarianskt paternalistiskt alternativ f¨oratt p˚averka val och beteenden { nudge teorin. Flera tidigare bepr¨ovade designverktyg betonas i denna teori. Nudge teorin har en dual process teoretisk bakgrund och kan delas in i tv˚atyper av nudging | Typ 1 nudg- ing och Typ 2 nudging. Bland Typ 1 verktyg v¨aljs default setting och manipulation of accessibility, och bland Typ 2 metoder v¨aljs reminders, prompts, framing och pre-commitment strategies. I syfte att illustrera detta anv¨andes s¨omn som exempel, d˚adet har l¨ankats till flera icke-smittsamma sjukdomar och f˚astudier har f¨ors¨oktatt unders¨oka motiverande design i relation till s¨omn.B¨attre s¨omnhygien ¨ar ett betydelsefullt verktyg f¨oratt f¨orb¨attras¨omnoch anv¨andesd¨arf¨orsom m˚als¨attning. Denna studie unders¨oker m¨ojligaalternativ f¨orpersuasive teknologi i syfte att f¨orb¨attras¨omn.Dessutom unders¨oktes potentialen av olika typer av persuasive teknologi och metoder f¨ornudging. Den valda metodologi ¨ar en informerad scenariobaserad design. Fem akademiskt anst¨allda,fyra m¨anoch en kvinna, med bak- grund inom interaction design, human-computer interaction, artificial intelligence och robotics, deltog i denna studie. Sju scenarion och tretton prototyper utarbetades f¨oratt illustrera en situation och presentera en m¨ojligl¨osningd¨ars¨omnhygien kunde f¨orb¨attrasigenom persuasive teknologi. Resultaten visade att Typ 1 nudging ans˚agsvara mer l¨ampligtoch effektiv. Emellertid bibeh˚allsk¨anslanav kontroll mer inom Typ 2 nudging. Default setting ans˚agssom mest effektiv inom betingelsen goal alignment, men med risk f¨orbakslag. Manipulation of accessibility b¨ordesignas s˚aatt navigering ¨arintuitiv och att integriteten av tillg¨anglighetinte st¨ors.Tajming ¨arden mest framtr¨adande faktorn f¨orreminders och de- ras p˚averkan skulle kunna framh¨avas igenom prioritering och cross-platform availability. Prompts skulle kunna framh¨avas mer igenom igenomt¨anktplacering d¨arl¨amplighet¨aren drivande faktor. Uppfattnin- gen av framing ¨armycket subjektiv och b¨orvara anpassad till anv¨andaren.Pre-commitment strategier har tillg˚angtill h¨ogremotivation men b¨orf¨orst¨arkas med andra medel. Sammanfattningsvis b¨orf¨oljande faktorer bet¨ankas inom motiverande design: goal alignment, intuitiveness, context awareness, availability och accessing motivation. Nyckelord: persuasive teknologi, nudge theorin, Typ 1 nudging, Typ 2 nudging, default setting, ma- nipulation of accessibility, reminders, prompts, framing, pre-commitment strategies, s¨omn, s¨omnhygien, scenariobaserad design 4 Exploring the Design of Nudging in Persuasive Technologies { Improving Sleep Hygiene In the past two decades, there has been an explosion of research on persuasive technologies for healthy behaviours, including physical activity (Lin et al., 2006; Anderson et al., 2007; Vandelanotte et al., 2016), healthy diets (Vandelanotte et al., 2016; Coughlin et al., 2015), weight loss (Pourzanjani et al., 2016; Turner-McGrievy and Tate, 2011), stress management (Sanches et al., 2010; Heber et al., 2016), glycemic control (Liang et al., 2011) and alcohol and smoking cessation (Lehto and Oinas-Kukkonen, 2011). These technologies provide feasible and appropriate means to assist primary care (Glasgow et al., 2004), which can help prevent non-communicable diseases (Vandelanotte et al., 2016; Peiris et al., 2014) and alleviate the financial burdens of healthcare systems (Elbert et al., 2014). Several theories of persuasion are often employed in persuasive health technology design, such as the reinforcement theory (Nakajima and Lehdonvirta, 2013), the elaboration likelihood model (Petty and Bri~nol,2011), the theory of planned behaviour (Ajzen, 2011), and the social conformity theory (Chiu et al., 2009). However, the moralizing effects of these well-intended persuasive technologies have the risk and tendency to be paternalistic and perceived as undesirable meddling (Verbeek, 2009). Hence, the current study puts forward a liberal, non-coercive alternative { the nudge theory. The nudge theory, or libertarian paternalism, is a behaviour change paradigm that uses indirect sugges- tions, positive reinforcement and takes advantage of judgemental heuristics and cognitive biases (Thaler and Sunstein, 2009). It has been extensively featured in behavioral economics studies (Acquisti, 2009; Tagliabue et al., 2019) sustainable food choices (Bucher et al., 2016; Vandenbroele et al., 2020) and public policies (Hansen and Jespersen, 2013; of Health, 2010). As opposed to the regulatory, paternal- istic and plausibly over-stepping approaches mentioned earlier, the nudge theory provides more gentle, indirect and liberal ways to help people make better choices. Moreover, the majority of technology-based interventions for healthy behaviour change use web-based services, mobile technologies, wearable devices and desktop applications (Orji and Moffatt, 2018). What these interventions have in common is that the interactions rely on single platforms or systems. However, our choices and behaviours are usually affected by multiple factors. To overcome the limitation of using single platforms/systems and create ubiquitous persuasive interactions, we are suggesting an omnipresent approach { incorporating nudges in the design of appliances and electronic devices. Nudging can be categorized in two types { Type 1 and Type 2, and the foundation of this differentiation is derived from the dual processing theory (Hansen, 2016). The theory entails the notion that there are two systems of thought processes { System 1, which is referred to as automatic thinking; and System 2, which is referred to as reflective thinking (Thaler and Sunstein, 2009; Kahneman, 2011).