The Influence of the Interface Button Design of Touch Screens on Operation and Interpretation by Elderly and Middle-Aged Adults

Abstract

Body function begins to decline in middle age, with changes becoming increasingly noticeable over time. With the popularization of educational and information technology, people know more about healthcare and are becoming accustomed to self-testing using health equipment. Technological changes are reflected in products, which present innovations including the switch from traditional to touch-controlled interface designs. This can cause difficulties in the interpretation and interface operation for older adults, who may be facing physiological and psychological alterations. Understanding users’ physiological limitations has become an important aspect of product design. This study explored the effects of physiological limitations on touch-screen operation in middle-aged and elderly people, specifically regarding button type, display position, and button size. A total of 64 participants were included in the study: 32 middle-aged people (aged 45–64 years) and 32 elderly people (65 years of age and older). Each participant was asked to complete 32 tasks (two button categories × four button sizes × four presentation positions). The results revealed no differences between the elderly and the middle-aged groups with regard to the interpretation of image buttons and text buttons; however, button size affected the operation and interpretation time. Middle-aged participants demonstrated good interpretation performance when the buttons were displayed in the upper or lower part of the screen, whereas elderly participants only had a good interpretation performance when the buttons were in the upper part. For both groups, the ideal image button size was 16 mm with a text font size of 22.