When a user interface component gains focus, it may not trigger a change of context. (Submission of a form, new window launch, immediate change of focus, changing content on the page where such that the purpose is different)
During manual evaluation, observe the interactions that occur when moving focus to new elements. The observation for this criterion is any situation when adding or removing focus from an element causes a major change of context.
A change of context is considered any situation where the user's focus or window changes such that the user no longer can reasonably understand where they are in relation to where they just were. Examples of changes of context include
Auto-submitting a form on focus (as opposed to clicking on a button or hitting the Return key).
Opening a new window or modal on focus.
Changing the contents of the page, such that the purpose of the content is altered. (It is okay to say close out of a popup in a navigation on a focus change, but not to dramatically change the page content on focus.)
