• success or results of an action
• waiting state of an application
• progress of a process
• existence of errors

... Read more about ✎ Technique: Status messages

Placement of controls affects their ease of use. For example, for a search feature, the “submit” button should be positioned right after the input field. Appearance and positioning are particularly important when providing a control that supports “destructive” actions, such as a “delete” or “clear” button. In these cases, ensure that these controls are clearly differentiated .... Read more about ✎ Technique: Differentiating controls

Autocomplete widgets can be helpful for accessibility because they can make it easier to enter text by providing suggestions based on the characters initially typed. This particularly helps people who find typing more difficult and people who may be susceptible to spelling mistakes.

Creating an accessible integrated autocomplete widget is a complex process. You need to ensure that screen-reader users are notified when the list of suggestions appears and that they can enter the list and select an option...

Providing form feedback accessibly helps users submit data more accurately and reduces the chance for error. For learning resources, easy access to feedback supports the learning process; for forms collecting data, good feedback helps to reduce the chance of input errors being made. 

When providing feedback on user input, JavaScript is often employed to print messages to the screen. Users looking at the screen will see the message appear in response to their actions. Screen-reader users who do not...

Modal dialogs can enhance usability by focusing attention on a specific message that requires a user action to continue.

An accessible modal dialog is one where keyboard focus is managed properly, and the correct information is exposed to screen readers. HTML and WAI-ARIA can be used to provide the necessary semantic information, CSS the appearance and Javascript the behavior.

Expandables (sometimes called “collapsible” or “disclosure widgets”) are simple interface patterns that allow you to expand and collapse content. They can be helpful accessibility aids as they give users the choice of revealing content to read it, or bypassing the content, making page navigation more efficient for screen-reader users and people using the keyboard or alternative input devices.

To ensure that they are accessible, it's important that expandable sections are coded so that their state (...

Accessible names are the labels given to HTML elements that can be announced in assistive technologies such as screen readers. They may or may not be visible to sighted interface users, depending on context.

Whether you provide controls using standard HTML elements or create custom controls, ensure that controls are given appropriate names. There are a number of ways to provide accessible names.

Descriptive labels help users understand the purpose of a form control. Labels should be associated with their controls so that when the input is focused, the label is announced by screen readers.

Icon fonts are a popular and effective method for providing scalable symbols that can be used to label controls and provide graphical information. The information provided by icons also needs to be available to people who can’t see them.