For the last few years, interface design in the domain of hypertext has mainly focused on the solution of the navigation problem. Moreover, browsing has been regarded as the most central user activity. While this claim may hold for hypertexts that do not demand a reader’s full attention, such as information kiosks or electronic advertisements, its validity must definitely be doubted for the majority of hyperdocuments. “Reading ... hypertext about matters that deeply matter to us” (Bernstein, 1991b, p.365) requires a lot more concentration and mental effort than careless node hopping. Therefore, navigation should not be regarded as an end in itself but as a mere precondition for the reader’s actual goal: the comprehension of the hyperdocument. Interface design focusing on this neglected issue may help to avoid what Foss (1989) has termed the “Art Museum Phenomenon” of hypertext, i.e., that “after you have spent a long day in a large art museum gazing a hundreds of paintings ... at the end of the day you may not be able to tell someone what you have seen” (p. 408). To overcome this phenomenon interfaces are required which significantly increase the readability of hyperdocuments.