Upvoted. A lot of articles are overusing hyperlinks in my opinion.

To be clear, hyperlinks are fine, to some extent. They can provide necessary information, and I can open them in new tabs and read later, which I usually do. On the other hand, starting from certain frequency they compromise the readability, especially when the reader cannot assume what is linked to. I can confirm that the discussed (otherwise very good) lukeprog's article can create impression of a "hyperlink abuse". It starts Some have suggested that... and all four of those words are hyperlinks.

What I find acceptable or even beneficial:

• Links to definitions of specialised terms which the audience may disinterpret (the term makes the link).
• Links to Wikipedia (or similar) page about a not well know person (the person's name is the link).
• Links to original sources of statements or quotes. If the quote is longer than two or three words, please don't transform the whole quote into a link; rather append "(source)" or something similar.
• Links to really relevant articles, if those are online.

What I find distracting:

• Links to unknown territory. I really appreciate if I know where the link will lead me. In the lukeprog's article mentioned above the phrase "instrumental rationality" links to Anna Salamon's LW article which does not include the string "instrumental" at all. It is not unreasonable to expect that such link would explain what "instrumental rationality" is; it doesn't.
• Links to Amazon pages about a book. Maybe I am mistaken, but I suppose people don't buy a book suggested by an internet article before they have finished reading the article. Also, the combination of the book's name and author is fairly unique and to find it on Amazon is quite straightforward. If books are linked to, I prefer doing it in a bibliography section.
• Long links. The Latin alphabet is kind of optimised for reading, but not so much when underlined. Long stretches of underlined text are hard to read.
• Lists of links disguised as normal text. Sometimes it is indeed appropriate to include a lot of similar links. If so, do it in a properly formatted list (preferably first briefly describing the link's content followed by the actual short link). It is difficult to navigate through seven links on the same line.
• Jargon definitions (sometimes). There are several phrases with more or less fixed meaning established often in the Sequences, and often when used they appear as a hyperling to the "defining" Sequence article. But consider: If the reader did read the relevant part of the Sequences and is an old LessWronger, she already knows the meaning. If not, using the jargon is not the best way to convey information, even with hyperlink included.
• Anything in the first list with too high frequency. For example definition of terminology: If a term is really important, its definition should be included, rather than linked to. If it is not important, it can be linked to, but it may be omitted. If the author thinks that the article can't be written without using fifteen concepts non-familiar to the readers, he would better not write the article at all, because before the readers pass through the fifteen links, they are likely to forget what the article is about. If the article doesn't desperately need to use all those concepts, it will be most likely more comprehensible not using all of them.

Edit: One more point: The author is supposedly more informed about the topic than the readers, and so he can more easily decide what further reading is indeed relevant. If the article contains eighty unsorted hyperlinks, the odds are that really relevant pieces are lost among distractions.