In the broadest sense, assistive technology is any technology which enables someone to do something they otherwise couldn't. A ladder, for instance, could be considered assistive technology, since it facilitates access to otherwise unreachable spots.

In the realm of computers and disability there are two general kinds of assistive technology. The first kind is technology that, by happenstance, involves a computer as part of its function (e.g., automated voice control of house electronics, or talking OCR software. While there isn't a real consensus on terminology, for the purposes of discussion, we will call this form of assistive technology "adaptive technology", as it is technology that helps someone adapt to their environment. The second kind of assistive technolgy is technology whose function it is to provide access to the computer system itself (e.g., a screen reader or screen magnifier for visual impairments, or keyboard alternatives, whether in hardware or software, for physical impairments). Here there is more consensus on terminology -- this is called "access technology," or more specifically, "access software," as virtually all of the action is in the software domain.

Adaptive technology places fairly modest demands on a computer system. Like any technology built on top of a computer system, it needs some basic things in order to perform its function (serial i/o support if it controls serial devices: speech input/output, if it listens/talks, etc.). Access technology makes rather greater demands of the computer system. Since access technology provides access to theoretically every aspect of every program running on that computer system to someone with a specific set of impairments, access technology needs to know potentially everything that is going on in the user interface of every program it is providing access to.

Relevant Laws

The main point behind all these laws is that they give students, state and federal employees, consumers, and their representatives the power to strongly influence future purchasing in a diverse set of public and private markets. The United States is the only country with disability-related laws on the books; however, the EU is highly sensitized to accessibility and has strong grant and research programs in place, and Japan sets hiring goals for companies and fines them if those goals aren't met.

Section 504 of the Federal Rehabilitation Act was passed in 1973 and applies to education contracts that utilize federal funds. It was passed so that students with disabilities could be mainstreamed into the regular public education system and could begin building the skills needed to compete in the job market. It basically states that federally funded technology purchases for education must include technologies and support for use by all students.

Section 508 of the Federal Rehabilitation Act is a sibling of Section 504 that was passed in 1986 and applies to all federal and state contracts that utilize federal funds. It has specific technology and information access requirements built into it, is focused on agency RFP writers, and is enforced by the General Services Agency. It was passed because purchases of inaccessible office automation technologies were forcing federal and state employees with disabilities out of their jobs, thus exposing the governmentsto potential antidiscrimination lawsuits.

The Americans with Disabilities Act (ADA) was passed in 1992 and applies to private companies. It requires commercial companies to reasonably accommodate employees in order to prevent discrimination. The interpretation of this law in large companies will end up tracking those found in Section 508.

The Telecommunications Act was passed in 1996 and covers any system that communicates across a wire to other systems. The definition and requirements associated with telecommunications accessibility haven't yet been passed, but it looks like federally funded purchases will fall under Section 508-like requirements and that technologies such as ATMs and public information kiosks will fall under ADA-like requirements.