A Case Study on the Design of Touchscreen-Based User Interfaces for Multilingual Older Adults from Southeast Asian Backgrounds Sumbul Khan Singapore University of Technology and Design umbul_khan@sutd.edu.sg Attila Achenbach Singapore University of Technology and Design Attila.achenbach@googlemail.com W. Quin Yow Singapore University of Technology and Design Quin@sutd.edu.sg Lucienne Blessing Singapore University of Technology and Design Lucienne_blessing@sutd.edu.sg ABSTRACT There is limited research on design guidelines for multilingual older adults, especially those with dementia, and from Southeast Asian backgrounds. In this paper, we investigate usability issues and user experience of a touchscreen-based dual-language cognitive inter- vention tool with cognitively healthy older adults and older adults in early stages of dementia from multilingual backgrounds. We present the iterative design and development process of our dual- language intervention tool, including usability and user experience testing with multilingual older adults. Our observations of usabil- ity issues and user experience during testing of the intervention tool with older adults primarily pertain to (a) language, (b) mo- tivation, and (c) user interaction. From the observed needs, we derived preliminary design guidelines for touchscreen-based user interfaces. Our observations and preliminary design guidelines for touchscreen-based user interfaces are signifcant due to their fo- cus on the needs of multilingual users older adults from Southeast Asian backgrounds. CCS CONCEPTS · Human-centered computing → Human computer interaction (HCI); Human computer interaction (HCI); HCI design and evalua- tion methods; Human computer interaction (HCI); HCI design and evaluation methods; User studies. KEYWORDS User Interfaces, Older Adults, Dementia, Developing Countries, Bilingualism, Accessibility, Design Guidelines, Serious Games ACM Reference Format: Sumbul Khan, Attila Achenbach, W. Quin Yow, and Lucienne Blessing. 2021. A Case Study on the Design of Touchscreen-Based User Interfaces for Multilingual Older Adults from Southeast Asian Backgrounds. In Asian CHI Symposium 2021 (Asian CHI Symposium 2021), May 08–13, 2021, Yokohama, Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for proft or commercial advantage and that copies bear this notice and the full citation on the frst page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specifc permission and/or a fee. Request permissions from permissions@acm.org. Asian CHI Symposium 2021, May 08–13, 2021, Yokohama, Japan © 2021 Association for Computing Machinery. ACM ISBN 978-1-4503-8203-8/21/05. . . $15.00 https://doi.org/10.1145/3429360.3468204 Japan. ACM, New York, NY, USA, 7 pages. https://doi.org/10.1145/3429360. 3468204 1 INTRODUCTION The world population of those aged 60 and above has been steadily increasing. Signifcant changes to the physical and cognitive abil- ities occur as people age, impacting how they interact with tech- nology. This is even more so for people sufering from dementia, estimated to be globally 5-8% of those aged 60 and above. Digital systems ofer older adults opportunities for leisure, health- care, and to stay both connected and independent. However, if the user interfaces are not designed with their special requirements in mind, these populations are often left behind. Several studies have investigated the use of touchscreen interfaces by cognitively healthy older adults (HC) 1 and persons with dementia (PwD)[1]. While user interface design guidelines for older adults and PwD have been explored to some extent and attempts have been made to gather design guidelines for older adults in general [2], user inter- face design guidelines specifcally for users with dementia are fewer and have been developed mostly in western, developed countries with a single dominant language. In a recent white paper, Babulal et al. [3] call for action on substantial ethno-racial knowledge gaps in dementia research. Especially, there is a need for greater research on the specifc user interface requirements of older adults and PwD living in Asian countries, home to more than half of the world population. There are two critical aspects that should be considered when designing user interfaces for older adults and PwD living in Asian countries. Firstly, these populations speak a diversity of languages and often no or little English [4]. Secondly, a signifcant number of this population have limited capabilities in reading and writing. Several leading Eastern Asian economies have an older adult literacy rate of around ∼80%, whereas it is as low as 35% on average in South Asia [5]. In a previous study, we explored attitudes towards technology as well as fne motor control of older adults using a touchscreen- based dual-language cognitive intervention tool (DISC) [6], [7]. The overall objective of this study was to investigate usability issues and user experience of DISC with HC and older adults in early 1 Cognition is considered as a combination of skills, such as attention, learning, memory, language, visual spatial skills. The term łcognitively healthyž has generally been used in literature to denote individuals with retained cognitive abilities, such as to think, learn and remember. 167