Five User Interface Design Tenets

Abstract

• A permanent, noninterrupting, and dynamic visualization is superior to text-based alerts to aid complex decision making during uncertain situations (Rayo et al., 2015). Dynamic visualizations are advantageous in that they (a) do not interrupt the operator, (b) visually present the risks and benefits of alternatives, and (c) promote comprehension and algorithm transparency of the decision support system. • With smaller keyboards being increasingly used today with portable devices, such as tablets and laptops, it is important that key spacing have a positive impact on typing performance and usability. A key gap of at least 3 mm and center-to-center key spacing of 17 mm is recommended to ensure higher typing accuracy (Madison et al., 2015). • Present dark characters on light background versus light characters on dark background when designing displays. This is especially advantageous with smaller font sizes to facilitate better perception of details (Piepenbrock, Mayr, & Buchner, 2014). The higher luminance provided by dark characters on a light background leads to higher pupillary contraction, increases the depth of field, and leads to higher acuity and superior perception of fine print. • With smartphones being used for myriad activities, such as social networking, messaging, and e-mailing by both younger and older adults, it is important to have reliable text entry methods. Smith and Chaparro (2015) showed that voice input is the most effective text entry method for younger and older adults alike, followed by physical Qwerty, tracing, onscreen Qwerty, and handwriting. Therefore, smartphone manufacturers should consider releasing smartphone models with physical Qwerty keyboards to gain a competitive edge. Handwriting is the least usable text entry method for both older and younger age groups. Tracing input is superior to onscreen Qwerty and handwriting among the onscreen input methods. • When designing large touch-screen user interfaces for young and old users, provide (a) click-to-zoom or drag-to-zoom options as well as a two-finger zooming gesture, (b) a click-to-rotate gesture design as well as a two-finger continuous rotating gesture, (c) touch-screen inclination angles of 60° to 75° to facilitate zooming and rotating, (d) button sizes that are at least 15.9 × 9 mm, and (e) dragging tasks that have right and downward movements (Gao & Sun, 2015).