Principle 2 — Flexibility in Use: Accommodating Diverse Preferences and Abilities

Flexibility in use, the second principle of universal design, requires that a design accommodate a wide range of individual preferences and abilities. Where equitable use focuses on equal access, flexibility focuses on offering multiple ways to achieve the same goal, recognizing that people differ in how they interact with the world.

Guidelines Under This Principle

The Centre for Universal Design identified four guidelines:

1. Provide choice in methods of use.
2. Accommodate right- or left-handed access and use.
3. Facilitate the user’s accuracy and precision.
4. Provide adaptability to the user’s pace.

Each guideline acknowledges a specific dimension of human variation. Handedness, motor control, cognitive processing speed, and interaction preferences all vary significantly across any population.

Physical Design Examples

Ambidextrous scissors are a classic example. Traditional scissors favor right-handed users because the blade orientation and handle shape assume a specific grip. Universal scissors either use symmetrical handles or feature reversible blade assemblies.

Adjustable-height desks accommodate users of different statures, wheelchair users, and people who alternate between sitting and standing throughout the day. The flexibility is built into the furniture rather than requiring users to adapt themselves to a fixed height.

Kitchen tools with interchangeable grips serve users with different hand sizes and grip strengths. OXO Good Grips, one of the most cited universal design product lines, originated from founder Sam Farber observing his wife’s difficulty with conventional kitchen tools due to arthritis.

Digital Design Examples

Modern operating systems exemplify flexibility in use through multiple input methods. A smartphone can be operated by touch, voice commands (Siri, Google Assistant), switch access devices, or external keyboards. The same task — sending a message — can be accomplished through any of these channels.

Web applications that support keyboard navigation alongside mouse interaction honor this principle. The W3C WAI’s WCAG 2.2 guidelines include specific success criteria (2.1.1 Keyboard, 2.5.1 Pointer Gestures) that ensure flexibility across input modalities.

Adjustable playback speed on video and audio platforms allows users to consume content at their preferred pace, benefiting both users with cognitive processing differences and users who simply prefer faster or slower playback.

Why Flexibility Matters

No two people interact with the world identically. Even within a single individual, preferences and abilities change over time and across contexts. A commuter might prefer voice input while driving but switch to typing at a desk. A worker recovering from a hand injury might temporarily need one-handed operation. Designing for flexibility means designing for the full reality of human experience.

Research published in the Journal of Accessibility and Design for All has shown that products offering multiple interaction pathways see higher adoption rates and longer user retention. Flexibility reduces the learning curve for new users by allowing them to start with a familiar modality.

Common Pitfalls

• Defaulting to one interaction mode — offering alternatives only in accessibility settings means many users never discover them. Flexible options should be visible and easy to switch between.
• Ignoring pace — timed interactions (auto-advancing carousels, session timeouts) penalize users who process information more slowly. WCAG success criterion 2.2.1 requires that time limits be adjustable.
• Assuming bilateral ability — designs that require two-handed operation exclude users with one arm, users carrying objects, and users with temporary injuries.

Flexibility in the Built Environment

Building codes increasingly reflect flexibility principles. The European Accessibility Act requires products and services to offer adaptable interaction methods. In architecture, the Centre for Excellence in Universal Design in Ireland recommends multi-height service counters, adjustable lighting, and rooms that can be reconfigured for different activities.

Wayfinding systems that combine visual signage, tactile maps, and digital navigation apps provide flexibility in how people orient themselves in unfamiliar spaces.

Connecting to Other Principles

Flexibility in use overlaps with simple and intuitive use — when multiple pathways exist, each individual pathway should still be straightforward. It also connects to low physical effort — offering alternatives ensures that at least one option minimizes strain for any given user.

For the full framework, see our overview of the seven principles.

Key Takeaways

• Flexibility in use means providing multiple ways to accomplish the same task, respecting the diversity of human preferences and abilities.
• Physical products, digital interfaces, and built environments all benefit from offering choice in interaction mode, handedness accommodation, precision support, and pace adaptability.
• Flexibility is not just an accessibility feature — it improves usability and adoption for all users across changing contexts.
• Visible, easy-to-switch alternatives outperform hidden accessibility settings.

Sources

• Centre for Universal Design, NC State — Principle 2: Flexibility in Use: https://design.ncsu.edu/research/center-for-universal-design/
• W3C — WCAG 2.2 Success Criterion 2.1.1 Keyboard: https://www.w3.org/TR/WCAG22/#keyboard
• Centre for Excellence in Universal Design — Principles of Universal Design: https://universaldesign.ie/what-is-universal-design/the-7-principles
• W3C — WCAG 2.2 Success Criterion 2.5.1 Pointer Gestures: https://www.w3.org/TR/WCAG22/#pointer-gestures