Links: How clearly laid out need they be?

To what extent should links be declared and clearly visible to the end user? Certainly links need to be differentiated within text but do links have to be clearly laid out everywhere? Can we assume the user will suspect that links exist if things are not explicitly laid out?

Most sites today, even sites made for the general reader have numerous linking methods. Is this a sign that users have passed the Jakob Nielsen threshold? Many have but I’ve seen many users never click on links. They look at the page and never even think of passing their cursor over text to see if a graphic or text is a link.

We assume that EVERYONE knows that an undifferentiated column of text would be thought of as a series of links. Not so. Clearly younger users seem to have an “intuitive” grasp of the possibility of linkage. It’s not intuition it’s curiosity and they lack the older users’ fear of “doing something wrong.”