Elements with ARIA widget roles must have event handlers that support the keyboard interactions required by those roles.
Purpose
Keyboard support is required by people who cannot use the mouse and/or gestures to select the options and perform the actions made available to them by interactive elements.
Native HTML4 and HTML5 link and form control elements have default keyboard interactions that are built-in and standardized among browsers.
When authors create custom interactive elements they need to support the keyboard interaction patterns that users have come to expect.
The ARIA Authoring Practices Guide identifies the keyboard interaction patterns that users expect and can rely upon, based on each ARIA widget role.
Information about the element associated with the result.
The information typically includes the tag name, accessible name or other information related to the rule requirements.
"Page" means that the result applied to the page. For example, the rule "One main landmark on the page" is a page level rule.
Element Position
The element position is based on the DOM order of elements in the page.
The element position maybe useful in helping to locate a specific element on the page evaluated (e.g smaller numbers are typically toward the beginning of a page and larger numbers typically toward the end of a page).
Element position 1 is the first element.
The highest element position is the last element.
Element position values for most rule/page results will not be consecutive since a rule only applies to a sub set of elements found on a page.