User-Centered System Design in an Aging Society: An Integrated Study on Technology Adoption by Chaiwoo Lee M.S. in Industrial Engineering, Seoul National University (2010) B.S. in Industrial Engineering, Seoul National University (2008) Submitted to the Engineering Systems Division in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Engineering Systems at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY June 2014 © 2014 Massachusetts Institute of Technology. All rights reserved. Signature of Author ................................................................................................................................... Engineering Systems Division May 23, 2014 Certified by ............................................................................................................................................... Olivier L. de Weck Professor, Engineering Systems Division and Department of Aeronautics and Astronautics Committee Chair Certified by ............................................................................................................................................... Joseph F. Coughlin Senior Lecturer, Engineering Systems Division Director, MIT AgeLab Thesis Advisor Certified by ............................................................................................................................................... Maria C. Yang Associate Professor, Engineering Systems Division and Department of Mechanical Engineering Committee Member Certified by ............................................................................................................................................... Lisa A. D’Ambrosio Research Scientist, MIT AgeLab Committee Member Accepted by .............................................................................................................................................. Richard Larson Professor, Engineering Systems Division Chair, Engineering Systems Division Education Committee 2 User-Centered System Design in an Aging Society: An Integrated Study on Technology Adoption by Chaiwoo Lee Submitted to the Engineering Systems Division on May 23, 2014 in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Engineering Systems Abstract The aging of the population is an important global phenomenon that is bringing changes and challenges to various areas of society. Technology has been explored as one way to cope with the complexities and uncertainties that are emerging with this demographic change. However, the responses from the potential user segment have been far from enthusiastic, suggesting that older adults’ adoption of technology is not simply a matter of performance and price, but a complex issue that is affected by multiple factors. This dissertation explores the topic of older adults’ technology adoption and use with an integrated framework that includes the perceptions, behaviors, and decisions of both the users and the producers. First, an exhaustive set of individual, technical, and social factors are identified and defined from a literature review and from user interviews with descriptions on these factors’ importance and roles in the adoption and use process. Second, the results from a large-scale national survey are presented with a discussion of the empirical validity of the factors, as well as their relative importance and associations at three main decision stages of adoption and use – purchase, initial use, and continued use. Finally, this dissertation presents a set of three cases developed from multiple sources of evidence on existing technology-enabled solutions for aging-in-place. The integrated framework described in this dissertation suggests the importance of considering population aging as a complex issue, as well as a new opportunity, that requires user-centered thinking from various players and stakeholders. Drawing on multiple methods of quantitative and qualitative data collection and analysis, the results underscore the importance and roles of different adoption factors during the design, development, and delivery of technology, as well as in older adults’ decisions around adoption and use. This dissertation finds that the various requirements, expectations, and values of older adults are closely related and collectively affect their decisions and behaviors around technology. Finally, a set of implications for research and practice are presented around the need for the continuous involvement of older adults throughout design, development, and delivery of technologies for a changing population. Thesis Supervisor: Joseph F. Coughlin Title: Senior Lecturer, Engineering Systems Division Director, MIT AgeLab 3 4 Acknowledgments I would first like to thank my husband Duyong for all his love and support during the course of my doctoral studies – first as my best friend, then as my boyfriend, and finally as my lifelong partner. This thesis would have been difficult to finish without his cheerful encouragements and timely distractions. I am grateful to have him in my life to laugh and cry together, and to support each other’s goals as well as our mutual aspirations. I am very fortunate to have a committee – Prof. Olivier de Weck, Dr. Joseph Coughlin, Prof. Maria Yang, and Dr. Lisa D’Ambrosio – who always made it their priority to be my mentors and to provide me with opportunities for academic and professional development. I always felt reassured and confident knowing that I have such strong, knowledgeable, and empathetic supporters. Especially, I would like to thank my advisors Joe and Oli for the generous support and meaningful discussions. I would also like to acknowledge my colleagues and friends at MIT, including those at the MIT AgeLab, Strategic Engineering Research Group (SERG), and the ESD Student Society (ESS). The conversations, collaborations, and critical reviews truly helped the advancement and progress of my research. My research and life at MIT was significantly supported by Samsung Scholarship in multiple ways. I would like to acknowledge the foundation for the academic funding and resources, and for providing me with a great network of scholars and peers across the globe. It is hard to find words to express my gratitude and appreciation enough for the love, care, help, trust, and patience that my family has shown. My father, Dr. Jong-Won Lee, served as an inspiration and a motivation as I went through the ups and downs of my life as a student. My mother Yongin has always been my role model and a great friend. Watching my parents bravely go through hardships and life challenges was more valuable than any advice or guidance that one could give. My brother Siwoo also deserves a special recognition for always being the best person to talk to and learn from. This thesis is dedicated to my family. 5 6 Contents Abstract ................................................................................................................................................. 3 Acknowledgments .................................................................................................................................. 5 1. Introduction and overview ............................................................................................................ 13 1.1. Motivation and background ....................................................................................................... 13 1.1.1. The aging of the population ................................................................................................ 13 1.1.2. Population aging as a complex systems issue ...................................................................... 15 1.2. Research questions and objectives ............................................................................................. 18 1.3. Thesis overview ........................................................................................................................ 19 2. Related works ................................................................................................................................ 20 2.1. Studies on technology adoption ................................................................................................. 20 2.1.1. Technology adoption models .............................................................................................. 20 2.1.2. Technology adoption among older adults ............................................................................ 26 2.2. Design of technologies for older adults...................................................................................... 31 2.2.1. User-centered product design and development ................................................................... 31 2.2.1.1. Process frameworks ...................................................................................................... 31 2.2.1.2. Methods of user studies for product design and development ........................................ 35 2.2.1.3. User-centered design principles .................................................................................... 38 2.2.2. Designing for older users .................................................................................................... 40 2.3. Lessons learned from related works........................................................................................... 43 3. Phase 1: Identifying factors of technology adoption .................................................................... 45 3.1. Factor