Silicon Valley based computer human interaction consultancy focusing on practical usability testing and interface design. Located in California, USA.

User interface design consultancy creating online, desktop, and handheld products and services. California, United States.

Usability and prototyping consultant focused on helping customers recognize, prioritize, and solve usability problems. Located in New Hampshire, USA.

Technology for persons with special needs and access for everyone.

Specialists in designing usable, useful and aesthetic interfaces for interactive products, ranging from software applications to handheld devices and medical equipment. Located in California, USA.

Customer research, information architecture and design, and usability evaluation of technology products and websites. Offices in Michigan, California, and New York, USA.

Provides details of the user experience consultancy services available, including usability, web accessibility and international user research.

Interactive application development and design consultancy focused on crafting effective Web experiences. Located in South Carolina, USA.

Independent usability and user-centred design consultancy, based in Stockholm, Sweden.

Provider of usability testing and research for websites, consumer electronics, software and hardware products. Located in Texas, USA.

The portfolio and resume of Kyle Pero, a usability analyst, interaction designer, and information architect consultant based in Pennsylvania, USA.

Provider of user experience services utilizing usability testing, focus groups, market research, training and documentation. Located in California, Georgia, and Illinois, USA.

Specializes in usability engineering, graphic design and software engineering, Serving Germany from Berlin, Dortmund, Ludwigsburg, Mannheim, and Munich.

Provides usability consulting, research, training and conferences. Located in Massachusetts, United States.

Consulting firm offering Web optimization services and information. Located in Michigan, USA.