Redundancy and Usability

David Ringholz, IDSA, Assistant Professor

Georgia Institute of Technology

Abstract:

From Norman’s Psychology of Everyday Things first published in 1988, to the Principles of Universal Design in 1997, experts in psychology, engineering, and design have worked to establish guidelines for usability. While the approaches and semantics differ, the goal has always been to be more inclusive by means of sensitive, responsible design. Originally, these efforts to define and guide usability were in response to products and environments that failed to meet the needs of a relatively small population. Lately though, there has been a shift in the characteristics of the viable market for Industrial Design products and services. Currently, there is a tremendous amount of diversity represented in terms of age, ability, culture and economic resource. This makes good design more challenging than ever.

Central to the competing and cooperative theories on usability is the tenet that the design should be flexible enough to accommodate a variety of users, irrespective of physical description, level of attention, level of experience or cultural background. Many of the techniques described to meet this goal of flexibility are redundant, in the most productive aspect of the word. Redundancy can be defined as providing multiple modes of interacting with a product. It gives the user the opportunity to use whatever senses, skills and knowledge they possess to have a satisfying and successful experience. Redundancy can be the feel a button has as it is pushed or an audible signal that alerts a user that the computer has finished a task. Voice dialing and voice command interfaces are examples of redundant input techniques for items like mobile phones and onboard navigation systems that ordinarily require visual and tactile input, allowing drivers to keep their eyes on the road and hands on the wheel. The impact can be subtle or profound; enhancing nonetheless.

While many examples of redundancy are enabled by technology, others are not. Designers have numerous opportunities for incorporating redundancy that are part of typical design execution, form, material, color, texture, sound, light and vibration. The shape of an object describes its orientation and function, texture on a grip surface denotes an area of action, a buzzer or light may signal warning. Good designs already feature many of these elements, but increased sensitivity to the benefits for various users might help designers tune their products for better performance and ease of use. The potential of using redundancy to maximize usability can be demonstrated in a project prepared for the IDSA and National Library Service for the Blind and Physically Handicapped Sponsored Digital Talking Book Playback Machine Student Design Competition.

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