Computer accessibility
Computer accessibility (also known as accessible computing) refers to the accessibility of a computer system to all people, regardless of disability type or severity of impairment. The term "accessibility" is most often used in reference to specialized hardware or software, or a combination of both, designed to enable the use of a computer by a person with a disability or impairment. Computer accessibility often has direct positive effects on people with disabilities. Accessibility features are meant to make the use of technology less challenging for those with disabilities. Common accessibility features include text-to-speech, closed-captioning, and  keyboard shortcuts. More specific technologies that need additional hardware may be referred to as assistive technology. There are many disabilities or impairments that can be a barrier to effective computer use. These impairments, which can be acquired from disease, trauma, or maybe congenital, include but are not limited to: A topic closely linked to computer accessibility is web accessibility. Similar to computer accessibility, web accessibility is the practice of making the use of the World Wide Web easier for individuals with disabilities. Accessibility is often abbreviated as the numeronym a11y, where the number 11 refers to the number of letters  omitted. This parallels the abbreviations of "internationalization" and "localization" as "i18n" and "l10n", respectively. Assessment for assistive technology use. People wishing to overcome an impairment in order to use a computer comfortably and productively may require a "special needs assessment" by an assistive technology consultant (such as an occupational therapist, a rehabilitation engineering technologist, or an educational technologist) to help them identify and configure appropriate assistive technologies to meet individual needs. Even those who are unable to leave their own home or who live far from assessment providers may be assessed (and assisted) remotely using remote desktop software and a  web cam. For example, the assessor logs on to the client's computer via a broadband Internet connection, observes the user's computer skills, and then remotely makes accessibility adjustments to the client's computer where necessary. Accessibility options for specific impairments. Cognitive impairments and illiteracy. The biggest challenge in computer accessibility is to make resources accessible to people with cognitive disabilities—particularly those with poor communication and reading skills. As an example, people with learning disabilities may rely on proprietary symbols and thus identify particular products via the product's symbols or icons. Unfortunately, copyright laws can limit icon  or symbol release to web-based programs and websites by owners who are unwilling to release them to the public. In these situations, an alternative approach for users who want to access public computer-based terminals in libraries, ATMs, and information kiosks is for the user to present a token to the computer terminal, such as a smart card, that has configuration information to adjust the computer speed, text size, etcetera to their particular needs. The concept is encompassed by the CEN standard "Identification card systems – Human-machine interface". This development of this standard has been supported in Europe by  SNAPI and has been successfully incorporated into the Local Authority Smartcards Standards e-Organisation (LASSeO) specifications. Visual impairment. Since computer interfaces often solicit visual input and provide visual feedback, another significant challenge in computer accessibility involves making software usable by people with visual impairments. For individuals with mild to medium vision impairment, it is helpful to use large fonts, high DPI displays, high-contrast themes and icons supplemented with auditory feedback and screen magnifying software. In the case of severe vision impairment such as blindness, screen reader software that provides feedback via text to speech or a refreshable braille display  is a necessary accommodation for interaction with a computer. About 8% of men and about 0.4% of women have some form of color-blindness. The main color combinations that might be confused by people with visual deficiency include red/green and blue/yellow. However, in a well-designed user interface, the color will not be the primary way to distinguish between different pieces of information. Motor and dexterity impairments. Some people may not be able to use a conventional input device, such as the mouse or the keyboard. Therefore, it is important for software functions to be accessible using both  devices. Ideally, the software will use a generic input API that permits the use even of highly specialized devices unheard of at the time of software's initial development. Keyboard shortcuts and mouse gestures are ways to achieve this access, as are more specialized solutions, including on-screen software keyboards and alternate input devices (switches, joysticks and trackballs). Users may enable a bounce key feature, allowing the keyboard to ignore repeated presses of the same key. Speech recognition technology is also a compelling and suitable alternative to conventional keyboard and mouse input as it simply requires a commonly available audio  headset. The astrophysicist Stephen Hawking is an example of someone with severe motor and physical limitations who used assistive technology to support activities of daily living. He used a switch, combined with special software, that allowed him to control his wheelchair-mounted computer using his limited and small movement ability. This personalized system allowed him to remain mobile, do research, and produce his written work. Prof. Hawking also used augmentative and alternative communication technology to speak and an environmental control device to access equipment independently. A small amount of modern research indicates that utilizing a standard computer mouse device improves  fine-motor skills. Hearing impairment. While sound user interfaces have a secondary role in common desktop computing, these interfaces are usually limited to using system sounds such as feedback. Some software producers take into account people who can't hear due to hearing impairments, silence requirements, or lack of sound-producing software. The system sounds like beeps can be substituted or supplemented with visual notifications and captioned text (akin to closed captioning). Closed captions are a very popular means of relaying information for the Deaf and hearing-impaired communities. Modern computer animation also allows for translation of content into sign  language by means of sign language avatars, such as SiMAX. Types of software accessibility. Accessibility application programming interfaces. Software APIs (application programming interfaces) exist to allow assistive technology products such as screen readers and screen magnifiers to work with mainstream software. The current or past APIs include: Some of these APIs are being standardized in the ISO/IEC 13066 series of standards. Accessibility features in mainstream software. Accessibility software can also make input devices easier to access at the user level. These include: Support for learning disabilities. Other approaches may be particularly relevant to users with a learning disability. These  include: Open Accessibility Framework. The Open Accessibility Framework (OAF) provides an outline of the steps that must be in place in order for any computing platform to be considered accessible. These steps are analogous to those necessary to make a physical or built environment accessible. The OAF divides the required steps into two categories: creation and use. The “creation” steps describe the precursors and building blocks required for technology developers to create accessible applications and products. They are as follows: The “use” steps describe what is necessary for the computing environment in which these accessible applications will run. They are  as follows: The following examples show that the OAF can be applied to different types of platforms: desktop operating systems, web applications and the mobile platform. A more complete list can be found in the Open Source Accessibility Repository by the Open Accessibility Everywhere Group (OAEG). The goal of the listed tools is to embed accessibility into various mainstream technologies. Positive effects of computer accessibility. Effects in school. Computer accessibility plays a large role in the classroom. Accessible technology can enable personalized learning for all students. Students who can benefit from personalized learning. In most classrooms, students can benefit from  the following: Impacts in the classroom. When accessible technology allows personalized learning, there are positive impacts on students. Personalized learning switches the focus from what is being taught to what is being learned. This allows the students to need to become an integral part of the learning process. Accessibility in the classroom allows millions of students of all backgrounds to have equal educational opportunities and keep up with their non-disabled peers. When PCs are personalized for students in the classroom, students are more comfortable in the classroom, special needs students are better assisted and teachers can save time and  effort. While PCs can provide a large amount of support in the classroom, iPads and apps can play a large role as well. Apps are constantly being developed to aid teachers, parents, and children. Educators have noted that the ease and portability of tablets make them a preferred choice that offers usage in a variety of environments. The advantages include interactivity, Internet access and text messaging. Educators have noticed improvements in motor skills, reading skills, and interaction with others in students. Impacts outside the classroom. Parents and teachers can notice the long-term effects that accessibility has on students with  disabilities. This can include enhanced social skills, better relationships with family and friends, increased understanding of the world around them, and an exhibition of self-reliance and confidence. Changes can be seen in not only children but adults as well. Social media can help parents to learn, share knowledge, and receive moral support. Effects in the workplace. Computer accessibility plays a large role in the workplace. In the past few years, adults have had their disabilities accommodated by the ability to work from home and by the availability of reliable software. This allows workers to work in a comfortable area  while still being able to support themselves. This is allowing thousands of people with disabilities to create and earn jobs for themselves. The inexpensiveness and reliability of computers has facilitated the process. Standards and regulations regarding computer accessibility. Section 508. Section 508 is a standard that is regulated by the United States Environmental Protection Agency. This department ensures that all information and communications technology is accessible to disabled users. Their responsibilities include designing websites, software, hardware, video and multimedia, and telecommunications that meet accessibility standards. The standards themselves were created by an independent federal agency that works on accessibility for  people with disabilities known as the US Access Board. International Standards. ISO 9241-171:2008 is a standard that provides ergonomics guidance and specifications for the design of accessible software for public use. Compiled from independent standards experts, this document is the most comprehensive and technical standard for designing accessible features for software, covering all disabilities and all aspects of software. It provides examples of two priority levels ('Required' and 'Recommended') and offers a handy checklist designed to help with recording software testing results. Because of its complexity and technical nature, and with upwards of 150 individual statements, ISO 9241-172  is difficult to interpret and apply. Luckily, not every statement is relevant to every situation, so it may be advisable to identify a subset of statements that are tailored to the particular software environment, making the use of this document much more achievable.