The Principles of Universal Design - 13 November 2005

by The Center for Universal Design

From the editor: the principles reprinted below was written in 1997. They have been carefully thought out by advocates of universal design. Principles like concepts do not change in time.

Read this article in Chinese (translated by Jacky Chan, proof read by Sean Liu)

The authors, a working group of architects, product designers, engineers and environmental design researchers, collaborated to establish the following Principles of Universal Design to guide a wide range of design disciplines including environments, products, and communications. These seven principles may be applied to evaluate existing designs, guide the design process and educate both designers and consumers about the characteristics of more usable products and environments.

How The Principles are formatted:

1. Name of the principle (a concise statement of the key concept embodied in the principle)
2. Definition of the principle (brief description of the principle’s primary directive for design)
3. Guidelines (list of the key elements that should be present in a design which adheres to the principle)
4. Images (photographic samples of the principles applied)

UNIVERSAL DESIGN:
The design of products and environments to be usable by all people, to the greatest extent possible, without the need for adaptation or specialized design.

PRINCIPLE ONE: Equitable Use

The design is useful and marketable to people with diverse abilities.

Guidelines:

• Provide the same means of use for all users: identical whenever possible; equivalent when not.
• Avoid segregating or stigmatizing any users.
• Provisions for privacy, security, and safety should be equally available to all users.
• Make the design appealing to all users.

PRINCIPLE TWO: Flexibility in Use

The design accommodates a wide range of individual preferences and abilities.

Guidelines:

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

PRINCIPLE THREE: Simple and Intuitive Use

Use of the design is easy to understand, regardless of the user’s experience, knowledge, language skills, or current concentration level.

Guidelines:

• Eliminate unnecessary complexity.
• Be consistent with user expectations and intuition.
• Accommodate a wide range of literacy and language skills.
• Arrange information consistent with its importance.
• Provide effective prompting and feedback during and after task completion

PRINCIPLE FOUR: Perceptible Information

The design communicates necessary information effectively to the user, regardless of ambient conditions or the user’s sensory abilities.

Guidelines:

• Use different modes (pictorial, verbal, tactile) for redundant presentation of essential information.
• Provide adequate contrast between essential information and its surroundings.
• Maximize “legibility” of essential information.
• Differentiate elements in ways that can be described (i.e., make it easy to give instructions or directions).
• Provide compatibility with a variety of techniques or devices used by people with sensory limitations.

PRINCIPLE FIVE: Tolerance for Error

The design minimizes hazards and the adverse consequences of accidental or unintended actions.

Guidelines:

• Arrange elements to minimize hazards and errors: most used elements, most accessible; hazardous elements eliminated, isolated, or shielded.
• Provide warnings of hazards and errors.
• Provide fail safe features.
• Discourage unconscious action in tasks that require vigilance.

PRINCIPLE SIX: Low Physical Effort

The design can be used efficiently and comfortably and with a minimum of fatigue.

Guidelines:

• Allow user to maintain a neutral body position.
• Use reasonable operating forces.
• Minimize repetitive actions.
• Minimize sustained physical effort.

PRINCIPLE SEVEN: Size and Space for Approach and Use

Appropriate size and space is provided for approach, reach, manipulation, and use regardless of user’s body size, posture, or mobility.

Guidelines:

• Provide a clear line of sight to important elements for any seated or standing user.
• Make reach to all components comfortable for any seated or standing user.
• Accommodate variations in hand and grip size.
• Provide adequate space for the use of assistive devices or personal assistance.

Please note that the Principles of Universal Design address only universally usable design, while the practice of design involves more than consideration for usability. Designers must also incorporate other considerations such as economic, engineering, cultural, gender, and environmental concerns in their design processes. These Principles offer designers guidance to better integrate features that meet the needs of as many users as possible.

IMAGE DESCRIPTION

Descriptions of the example images for the Principles of Universal Design.

principle one: equitable use

Image Description
Two shoppers, one pushing a cart and the other using a power wheelchair, pass through open automatic doors.

principle two: flexibilty in use

Image Description
Large grip scissors are shown being held in the left hand, another in other in the right hand.

principle three: simple and intuitive

Image Description
Imported furniture instructions illustrate assembly without written directions.

principle four: perceptible information

Image Description
A person with low vision operates at close range a round thermostat with large numbers, tactile indicators, and audible cues.

principle five: tolerance for error

Image Description
Computer menu shows the arrow pointing to the “undo” function.

principle six: low physical effort

Image Description
A hand with closed fingers operates a lever door handle by pushing down.

principle seven: size and space for approach and use

Image Description
A woman in a power wheelchair passes through a wide subway gate.

Compiled by advocates of universal design, listed in alphabetical order: Bettye Rose Connell, Mike Jones, Ron Mace, Jim Mueller, Abir Mullick, Elaine Ostroff, Jon Sanford, Ed Steinfeld, Molly Story, and Gregg Vanderheiden.

Major funding provided by: The National Institute on Disability and Rehabilitation Research, U.S. Department of Education

Copyright 1997 NC State University, The Center for Universal Design

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• Moving UX into a Position of Corporate Influence: Whose Advice Really Works?
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