Overview
ISO/IEC 17549-3:2023 - published by ISO/IEC - defines user‑interface requirements and recommendations for menu navigation with one‑direction devices (single‑switch and double‑switch). The standard focuses on accessible, predictable menu selection for devices where navigation is possible only in a single direction, specifying rules for time delays, loops, focus rendering, and other scanning behaviors. It applies to any information‑technology equipment whose display area is associated with one‑direction controls (including virtual or physical controls used by motor‑impaired users).
Key topics and technical requirements
- Device types: Defines single‑switch devices (one key → requires automatic scrolling) and double‑switch devices (two keys → manual next + activation).
- Menu structures:
- Ladder menus: Short menus (≤7 items) should place the “back” item at the end; long menus (>7 items) need “back” items at least every 10 items or an alternate method.
- Tile menus: On a single screen, “back” items at top and bottom; for multi‑screen tile menus, place “back” items at the end of every third line.
- Navigation mechanics:
- Automatic scrolling for single‑switch devices (each item must be focused during automated navigation).
- Manual scrolling for double‑switch devices (first key moves to next item; second key activates).
- Loops and sub‑loops: Menus shall support loops (last → first), with separator bars to indicate boundaries; sub‑loops must include a “back” command. Hierarchy depth should not exceed five levels; deep hierarchies should provide direct access to the menu bar.
- Focus and indicators:
- Focus rendering must be available via visual, auditory, and/or tactile feedback.
- Audio feedback required when an item is focused/activated, with user option to disable audio.
- The next focused item must be fully visible before focus changes.
- Timing and ergonomics: The standard addresses scanning speed, start/pause and post‑activation delays, re‑scan/skip behaviors to reduce cognitive load and fatigue (see Clause 6 for conformance requirements).
Applications and users
- Targeted for designers and implementers of accessible user interfaces, including:
- UI/UX designers, accessibility engineers, product managers
- Assistive‑technology and AAC device manufacturers
- Mobile phone and embedded device developers with constrained input
- Regulatory and procurement teams specifying accessibility requirements
- Practical use cases: menu navigation on AAC devices, sip/puff switches, single‑button remote controls, gesture‑based one‑direction inputs, and simplified mobile interfaces for motor‑impaired users.
Related standards
- ISO/IEC 17549‑2:2020 - User interface guidelines on menu navigation with 4‑direction devices (referenced normative document).
Keywords: ISO/IEC 17549-3:2023, one-direction devices, single-switch, double-switch, menu navigation, accessibility, automatic scrolling, focus rendering, ladder menu, tile menu, assistive technology.