Non-Visual Haptic Interaction Design
Guidelines and Applications
DOCTORAL DISSERTATION, ISBN 91-628-5412-7
This dissertation has three cornerstones:
- Human-Computer Interaction (HCI)
- Blind Users
Haptics deals with controlling human movements and getting feedback
through the sense of touch. A haptic interface transmits forces to a
persons hand or fingers in a way that mimics the sensation of
touching real objects. Virtual haptic touch can be particularly useful
for people with visual impairments. It makes it possible for a blind
person to touch virtual objects, corresponding to the way a sighted
person can see objects on a computer screen.
The goal of this research was to carry out an unbiased investigation of
the potential of this technology for blind people. The more specific
aims were to:
- Investigate if and how blind peoples computer usage can be
improved by virtual haptics.
- Investigate the problems that arise with graphical user interfaces
for blind people and how these problems can be managed with haptics.
- Develop new applications and find new areas in which virtual haptics
can be applied for blind people.
The design process has been primarily influenced by theories of
usability engineering and reflection in action/reflection on action,
focusing on the role of the engineer-designer. A concerted effort is
made to use technology as a language to communicate with the users.
Several haptic interface devices have been involved. The Phantom from
SensAble Technologies has been used the most. It is a small robot with a
thimble or stylus attached to the tip which supplies force feedback to
the user. The others are the FEELit Mouse from Immersion and the force
feedback joysticks from Logitech and Microsoft.
Eighteen test applications were developed over five years time. They
included games, curves, textures, drawings, menus, floor plans, and
geometrical objects. Formal and informal user tests were performed on
blind, blind-deaf and sighted people.
One of the key results presented are five guidelines for non-visual
haptic interaction design for researchers, designers, testers,
developers and users of such applications. The guidelines are:
- Elaborate a virtual object design of its own
- Facilitate navigation and overview
- Provide contextual information
- Utilize all available modalities
- Support the user in learning the interaction method and the
specific environments and programs
These guidelines represent the filtered and condensed knowledge and
experience that the Haptics Group at Certec has gained during the
testing and development process. They are further delineated and are a
complement to existing HCI guidelines.
This work shows that there is great potential in using haptic technology
in applications for blind people. It is viable to translate both 2D and
3D graphical information and make it comprehensible via haptics. It has
been demonstrated that a blind person can orientate and navigate in a
virtual haptic environment and that these tasks can be further supported
by using complementary information such as sound and Braille. It is also
possible for a blind person to use knowledge gained in the virtual world
for real life orientation.