Copyright is owned by the Author of the thesis. Permission is given for a copy to be downloaded by an individual for the purpose of research and private study only. The thesis may not be reproduced elsewhere without the permission of the Author. Usability of disaster apps: Understanding the perspectives of the public as end-users A dissertation presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Emergency Management at Massey University, Wellington, New Zealand Marion Lara Tan 2020 Ad majorem Dei gloraim ABSTRACT Multiple smartphone applications (apps) exist that can enhance the public’s resilience to disasters. Despite the capabilities of these apps, they can only be effective if users find them usable. Availability does not automatically translate to usability nor does it guarantee continued usage by the target users. A disaster app will be of little or no value if a user abandons it after the initial download. It is, therefore, essential to understand the users’ perspectives on the usability of disaster apps. In the context of disaster apps, usability entails providing the elements that effectively facilitate users in retrieving critical information, and thus enabling them to make decisions during crises. Establishing good usability for effective systems relies upon focussing on the user whereby technological solutions match the user’s needs and expectations. However, most studies on the usability of disaster context technologies have been conducted with emergency responders, and only a few have investigated the publics’ perspectives as end-users. This doctoral project, written within a ‘PhD-thesis-with-publication’ format, addresses this gap by investigating the usability of disaster apps through the perspectives of the public end-users. The investigation takes an explicitly perceived usability standpoint where the experiences of the end-users are prioritised. Data analysis involved user-centric information to understand the public’s context and the mechanisms of disaster app usability. A mixed methods approach incorporates the qualitative analysis of app store data of 1,405 user reviews from 58 existing disaster apps, the quantitative analysis of 271 survey responses from actual disaster app users, and the qualitative analysis of usability inquiries with 18 members of the public. Insights gathered from this doctoral project highlight that end-users do not anticipate using disaster apps frequently, which poses particular challenges. Furthermore, despite the anticipated low frequency of use, because of the life-safety association of disasters apps, end- i users have an expectation that the apps can operate with adequate usability when needed. This doctoral project provides focussed outcomes that consider such user perspectives. First, an app store analysis investigating user reviews identified new usability concerns particular to disaster apps. It highlighted users’ opinion on phone resource usage and relevance of content, among others. More importantly, it defined a new usability factor, app dependability, relating to the life-safety context of disaster apps. App dependability is the degree to which users’ perceive that an app can operate dependably during critical scenarios. Second, the quantitative results from this research have contributed towards producing a usability-continuance model, highlighting the usability factors that affect end-users’ intention to keep or uninstall a disaster app. The key influences for users’ intention to keep disaster apps are: (1) users’ perceptions as to whether the app delivers its function (app utility), (2) whether it does so dependably (app dependability), and (3) whether it presents information that can be easily understood (user-interface output). Subsequently, too much focus on (4) user-interface graphics and (5) user-interface input can encourage users to uninstall apps. Third, the results from the qualitative analysis of the inquiry data provide a basis for developing guidelines for disaster app usability. In the expectation of low level of engagement with disaster app users, the guidelines list recommendations addressing information salience, cognitive load, and trust. This doctoral project provides several contributions to the body of knowledge for usability and disaster apps. It reiterates the importance of investigating the usability of technological products for disasters and showcases the value of user-centric data in understanding usability. It has investigated usability with particular attention to the end-users’ perspectives on the context of disaster apps and, thus, produces a theoretical usability-continuance model to advance disaster app usability research and usability guidelines to encourage responsible design in practice. ii PREFACE I was nine months into my PhD, and nine months new to New Zealand, when the 7.8M Kaikōura earthquake struck at two minutes past midnight on November 14, 2016. The shaking I felt on that night, in Wellington, was nothing like I have ever encountered in all my years living in the Philippines. During the two-minute-long shaking, I crouched under my study desk. It felt like our two-storey wooden house became a small boat, waiting to be torn apart by the waves of rough seas. When the shaking subsided, I left my room. Seeing my housemates in the hallways, we all quickly evacuated to our back garden, unsure whether the severity of the ground motion damaged the structural integrity of our home. Despite the mild and clear spring night, it still felt cold to be out in the open, especially since we went out only wearing our sleeping clothes. None of us brought jackets, blankets, emergency bags, or torches with us. However, all of us brought out one thing: our smartphones. Despite the gravity of the event, mobile and internet connectivity was still intact. Huddled outside in the dark, reeling from the aftershocks, all of us got onto our devices. With my hands shaking, I used whatever relevant apps I had at the time to figure out the details of the earthquake and to connect with my family and friends to let them know I was alright. The Kaikōura earthquake killed two people, destroyed infrastructure, disrupted local economies, and unsettled many lives. I would rather the event had not happened, but, at the moment we all used our smartphones in the dark, I knew I needed to continue to pursue my iii ACKNOWLEDGEMENTS My PhD story is not one without challenges, but I thoroughly enjoyed the entirety of the experience thanks to the support and love I received from so many people. My sincerest gratitude goes to Dr Raj Prasanna, my primary supervisor, for being there every step of the way. He saw through my insecurities in engaging in socio-technical research and mentored me to develop skills and helped me gain confidence as a researcher. I will not be the researcher I am today without him. I have been privileged to have a caring supervision team who gave me their time, energy, and enthusiasm. Each one had a unique way of providing guidance that made my work holistic. Dr Kristin Stock asked the challenging questions that made my research robust. I am grateful for her thought-provoking yet encouraging perspectives. Dr Emma Hudson-Doyle asked the ‘why’ questions, allowing me to see the bigger picture. I am thankful for her detailed, constructive, and reassuring feedback. Dr Graham Leonard grounded my research to practice by providing the opportunity to engage with the alerting research community in New Zealand. His guidance was instrumental in the development of my data-gathering methods. Professor David Johnston strengthened my work by giving me platforms to share my research with the national and international research communities. I am grateful for his constant support throughout my PhD. My sincere thanks go to Deborah Smith, Marcus Bird, and Kevin Fenaughty for allowing me to learn from, and contribute to, the New Zealand Red Cross Hazard working group and the Common Alerting Protocol working group. My immersion in these groups shaped my perspectives on apps and alerting, and made me strive to do useful research. I also thank my survey respondents, usability inquiry interviewees, expert evaluators, and pilot testers—my PhD would not be possible without their participation. My PhD was funded by the New Zealand International Doctoral Scholarship and the Massey University College of Humanities and Social Sciences Doctoral Scholarship. I could not do the PhD without their generous financial support. v My special thanks goes to the Joint Centre for Disaster Research (JCDR) community. I would not have enjoyed this experience without the company of the PhD students who walked with me through the ups and downs of the PhD journey. My love to Dr Nancy Brown, Dr Mina Adhikari, Miles Crawford, Syed Yasir Imtiaz, Lisa McLaren, Ashleigh Rushton, Sara Harrison, Lesley Gray, Bruce Pepperell, Rangika Nilani, and Ayisha Shaik. My life in JCDR was also made vibrant with the presence of the staff, post-docs, interns, and visiting scholars. I want to acknowledge Abi Beatson, Liza Hoefnagels, and Noriko Imura for their care during their time at the centre. It was challenging to be away from family while doing this PhD. However, I found different ‘families’ in New Zealand that sustained me. The Kia Maia International Student Hostel was my home for three years under the loving care of Rosemary and Graeme Wallis, and Naomi Afoa. I am grateful for the gifts of friendship from: Ye Tingting (Lindsay), Laura and Ed Holden, Pravin Thayaparan, Transi Phu, Naoto Shiota, Janice Liaw, and Teh Meng Hing. I also want to thank the New Zealand Focolare Movement, particularly to Miriam Vender, Philip Wakelin, and Cris Sebold. Not by deliberate intention but just by their loving presence they shone light in some of my darkest moments. I started practising aikido mid-way through the PhD, and I am thankful to Riai Aikido for providing me respite from academic life. My special thanks to Victor Sugijarta and Marceau Bole-Richards for their friendship off the mat.