In the Using ARIA document (working draft) (as well as the latest published docs), the text above the second code sample says that the code shows a <label> being associated with its input. But the code sample uses aria-label & aria-labelledby instead.
Text:
In comparison, the input type=text in the code example below has a visible label 'user name' and an accessible name. This example has an accessible name because the input element is a labelable element and the label element is used correctly to associate the label text with the input.
Code sample (note that even the code comment does not match the code)
<!-- Note: use of for/id or wrapping label around text
and control methods will result in an accessible name -->
<input type="text" aria-label="User Name">
or
<span id="p1">user name</span> <input type="text" aria-labelledby="p1">
In the Using ARIA document (working draft) (as well as the latest published docs), the text above the second code sample says that the code shows a
<label>being associated with itsinput. But the code sample usesaria-label&aria-labelledbyinstead.Text:
Code sample (note that even the code comment does not match the code)