In a perfect world, all browsers would somehow notify users when links lead
to destinations on the same page. In the real world, only screen
reader users have this information announced to them. JAWS says "same
page link" before every such link. Sighted users can look at the
status bar in the lower left corner of their browser to read the
full link text, but this is a less convenient method of finding out
where the link goes, because it is essentially a trial and error
method. Users would have to hover over every link to know for sure
where each leads. Plus users have to decipher the URL, which can
be quite difficult to decipher, as has been discussed.
Accessibility advocates could complain about the fact that users don't know
whether links go to the same page or not, but for some reason, this
has not been high on anyone's list of accessibility problems to complain
about. One possible reason for this has already been mentioned: the
fact that screen readers already notify users of link destinations—even
though the rest of the world does not have easy access to this information.
Another reason may be that the context of a web page often gives
clues as to the link destination. A collection of links at the top
of a page but below the main navigation, for example, probably all
lead to destinations on the same page, at least if the collection
of links appears to be a table of contents for the page.
Nevertheless, it is appropriate to provide cues to users if the link goes
to a destination on the same page. To help users better understand
the context, it could be helpful to place a heading above the collection
of links that says "page
or something to that effect. Other situations and contexts may
call for different kinds of techniques.
Firefox users can install the TargetAlert extension to differentiate
between same-page links, links to external pages, links to
external web sites, links which open new windows, and other
conditions. In each case, it places an icon after the link,
as shown in the screenshot below:
See the TargetAlert web site - external link to learn about or download the software.