D - F

Table of contents

D

E

F

D

data table

A means of organising data in neat labelled columns and rows.

decibel

A unit measuring how loud a sound is.

definition list

A means of ordering information via HTML using the <dl></dl>, <dt></dt> and <dd></dd> tags. A definition list should consist of a word or phrase and then a list of bullet points explaining that word or phrase.

dementia

According to the the Alzheimer's Association, dementia is a set of symptoms of specific diseases or conditions such as Alzheimers, aging, alcoholism, depression and more. These symptoms can include problems with thinking and memory loss, loss of reasoning skills, personality changes and mood swings.

deprecated markup

An HTML or XHTML tag that is no longer in use in newer versions of the language. As these tags may be completely discarded in the future it is best not to use them.

device independent

A program, file or webpage which can be accessed no matter what computer, or other device such as PDA or mobile phone the user has or what software they use.

diabetic retinopathy

A side effect of diabetes, it affects the blood vessels in the retina and can cause blurred vision and potentially blindness.

dial-up

Internet access which requires you to phone your service provider using a modem in order to connect.

Disability Discrimination Act (DDA)

UK act making it illegal to discriminate against people with disabilities. Passed in 1995, it applies to all businesses including websites.

disabled (script, stylesheet, etc.)

In regards to aspects of a web page, disabled means that the user has set up their browser so they cannot run scripts or see the presentation settings of the style sheet or see images, etc.

div

A div or division is indicated by the <div> tag on a web page and represents sections of a website which are ordered in a style sheet. Divs enable web designers to organise their page without using tables for layout.

doctype

The doctype or <!DOCTYPE> tag tells the browser what version of HTML or XHTML is used to design the page so it knows how to read and display the page.

dropdown box

A box, similar to a text box, which, when highlighted, displays a range of choices to the user.

dynamic content

Dynamic content is content of a web site which changes depending on the user, the date, time of day or specified preferences. It usually requires the use of scripts.

dyslexia

Dyslexia is the description of a cognitive disability characterised by difficulties with reading, spelling and counting. People with dyslexia process information differently and may have trouble following instructions, interpreting written language and with working memory. These problems are un-related to intelligence and merely mean that a person with dyslexia may need the information on a web page presented in a different way from the "average" user or may need more time to find the information they need.

E

encoding

To format the text characters in a way that the browser can understand what they are.

exponential

A quantity that gets bigger at a rate which is related to its size. The bigger it gets the faster it gets bigger, but in proportion.

extreme changes of context

An extreme change of context is something which happens on a web page that the user would not have expected.

F

fixed width

An item or section of layout on a web page which will not resize if the user magnifies the page.

fixed width font

Non-proportional font or a font which will not resize if the user tries to magnify or shrink a web page.

Flash

Flash is a program used to create multimedia content which can involve graphics, animation and/or sound. It requires the user to have a plug-in to enable them to see the content. If Flash content is not designed correctly it is impossible for screen readers to access it, for keyboard users to access navigation created in Flash and for people using text browsers to see Flash content.

Flesch-Kinkaid

The Flesch-Kinkaid readability formula measures how hard a passage of text is by saying what school year it would be appropriate for. It looks at the length of sentences and the difficulty of words. See our article on Readability Indexes for more information.

focus

Focus is the window or place on a web page that is highlighted. The window which has focus is the one at which you are currently looking or reading. The part of a web page which has focus is the link, form field or other item which is highlighted and will activate if the "enter" key is pressed.

font size

Font size is how big the text on a web page is. Font size can be absolute or fixed which means it will remain the same even if magnified. Ideally, it is relative which means it stays a certain size in relation to the size of the other elements of the page around it.

foreground colour

The foreground colour is the colour of the text or of the image which is sitting on the page.

form field

A form field is the text box, dropdown selection box, checkbox or radio button which needs to be filled with information from the user.

frame

A frame is where a webpage has been organised into different sections with each section being a unique HTML document with its own title and source code. Each one of these sections is a frame.