From Jakob Nielsen's Alertbox post on
"Windows Vista introduced a new GUI widget for commands: the command link. Once something is in the system that people use on a daily basis, it becomes a de facto standard. Because they'll encounter them frequently in Vista, users will come to know and expect command links."
From what I gather, Vista 'command links' appear to be glorified buttons for native applications, not 'underlined text' links on Web pages.
However, Jakob continues with the following regarding web page links:
To reduce confusion, link text should explicitly state that it leads to an action and not just to a new page. It's not enough to communicate this info in the surrounding text; users often scan Web pages for the areas they can act on. Thus, you should assume that most users will only read the link text. In fact, users often read only the link text's first few words, so it's important to start with a word (typically a verb) that indicates the action that results if they click the link.
It appears Jakob is also implicitly approving the use of a link on a web page as an 'action'. From my reading, I think this is seriously wrong. I believe web page 'action links' need to satisfy the following two requirements
- visually distinct from normal 'safe' links
- syntactically distinct from normal 'safe' links
The second point is important because of the large number of automated agents that traverse the Web through hyperlinks. Adding unsafe links into the web will cause confusion among both people and software agents.