Early in the development of hypertext, Guido van Rossum suggested that EMBEDs might provide an alternate type of link:
Quoting van Rossum
Some other hypertext systems do this, in a sense: in Guide there are,
apart from real GOTO type hyperlinks, also "folds" (I think they are
called) which are sort of embedded documents that you can open and
close. The advantage in certain situations is that opening a fold
retains more context than following a link. It feels like using an
outline processor, which is rather pleasant (for certain kinds of
information). html 
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Marc Andreessen suggested that there was little difference.
Quoting Andreeesen
Aside from this, I'm
not sure I see the point in allowing arbitrary EMBED's for things like
chunks of texts: this is a hypertext system, after all, and it ought
to be possible to get the functional effect of an EMBED by using an
ordinary link. Right? html
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Usability expert Jakob Nielsen's research from the 1980s disagreed with this point though:
Quoting Nielsen
Getting lost seems to be a worse user interface problem than navigation itself. In a small field study I did of a Guide document, users found the reference button (which is the one that really moves you to a different place in the structure) significantly less easy to understand and less of a usability/readability improvement than the note button and the replacement button [about a difference of one whole point for each question on a 1-5 Likert scale].
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