Accessibility refers to the extent to which something can be utilised by a wide variety of people, rather than effectively only by those with a particular level of health and abilities. Accessibility issues include things like:
- Web sites that are unusable for blind people using screen readers;
- buildings which cannot be entered or navigated by people in wheel chairs;
- public announcements only being made aurally, such that they are unavailable to the deaf.
It should not be assumed, however, that accessibility only matters to people who are typically regarded as 'disabled' in some form. For example, a Web site whose content is primarily provided via video might not be practically accessible to those people who, for whatever reason, only have a dial-up connection. It might be that the cost of broadband is prohibitive for those people; thus the Web site has accessibility issues for the poor.
It is also important to remember that differing levels of health and ability are not always immediately apparent: just because a person is not in a wheelchair, for example, does not mean that they don't face serious mobility issues (e.g. they might suffer from Chronic Fatigue Syndrome), and mental health issues such as major depression might not manifest in any particularly obvious ways. Additionally, levels of ability differing from those commonly regarded as 'acceptable' are not necessarily disabilities: in some instances they may in fact be simply representative of human diversity.
Language difficulties are often missed when considering creating communities, while clear and understandable text is important for good communication, policing of spelling and grammar can make a community inaccessible to a dyslexic person or a person from a for whom the forum is in a second language.
Accessibility is an important issue to consider when attempting to minimise exclusion from a community and maximise community participation.