In many situations, covered entities communicate with someone other than the person who is receiving their goods or services. For example, school staff usually talk to a parent about a child’s progress; hospital staff often talk to a patient’s spouse, other relative, or friend about the patient’s condition or prognosis. The rules refer to such people as “companions” and require covered entities to provide effective communication for companions who have communication disabilities.
Federal law isn't the only consideration for businesses. Additionally, each state interprets the law differently. Consider the case against Netflix in 2012. Lawsuits were brought in federal court in Massachusetts and California. Netflix was accused of violating the ADA by not offering "closed captioning" options for its Internet streamed movies. Illustrating the complexity of this issue, the courts reached completely opposite decisions. Massachusetts held that Netflix must comply with the ADA, while the California court found that Netflix did not fall under the ADA's definition of "public accommodation."
Motor/Mobility: Voice recognition software, touch screens, head/mouth wands, special switches, keyboard overlays, one-handed keyboards, oversized mouse or trackball are some of the tools a user with limited mobility may use, but for testers, all you’ll need is a traditional keyboard to test. Ensure that there is a logical tab order (left to right, top to bottom) and provide logical and standard keyboard commands. Tab through the site and visually see if the tabbing order is logical (usually known as OnFocus). If an element is skipped or the tabbing order doesn’t make sense to you as a tester, that could possibly be an issue of ADA compliance.
Poorly designed websites can create unnecessary barriers for people with disabilities, just as poorly designed buildings prevent some people with disabilities from entering. Access problems often occur because website designers mistakenly assume that everyone sees and accesses a webpage in the same way. This mistaken assumption can frustrate assistive technologies and their users. Accessible website design recognizes these differences and does not require people to see, hear, or use a standard mouse in order to access the information and services provided.