The purpose of notes is to present citations, background, or further discussion and background that doesn’t belong in the text. (Also: snarky jokes.) The design challenge of notes is to 1) indicate that there is a note, 2) provide a reference to that note, and 3) print the note in a place where it can be accessed. The very existence of notes implies 4) not unduly interrupting the flow of the main text.
Footnotes and endnotes are in essential agreement on points 1 and 2. They provide superscripted numerals (or occasionally symbols) as a reference key, with the corresponding number opening the note in the notes section. Parenthetical notes are barbarous and should not be used by anyone, ever. For those who are required to use them for departmental reasons,1 my sympathies for finding yourself amongst fools.
Where footnotes and endnotes disagree is along the spectrum of design challenges 3 and 4. Endnote advocates seem to prefer 4 to 3, keeping the main text clean and relegating notes to a separate section that nobody ever reads so that authors can be dishonest. In other words, endnotes advocates are either liars or supporters of liars.
Footnotes, on the other hand, favours design challenge 3 by placing the relevant note content at the bottom of every page where they are easily accessed. Properly designed footnotes will never interrupt or distract from the main text, so 4 is not really an issue.2 The beauty of footnotes is that they can and are read when desired. Nothing beats a good joke or rambling tangent in a footnote.
Parenthetical notes succeed on points 1-3. You are aware there is a note, you don’t need to track it down, and it is immediately accessible. But it is such a catastrophe on point 4 that it produces ugly text that no sane person wants to read. Because it interrupts the text so oafishly, those who employ parenthetical notes never use them for more than citations, which is the least interesting (but still needed) form of note.
These three notes forms are print-based and you may at this point be wondering how this all translates onto the web. This very article utilizes footnotes, which could seem like an attempt to inappropriately stuff print metaphors into a foreign medium. What about notes designs that are web-native? Since there’s no pagination on the web, aren’t my footnotes really just endnotes with easier access throught linking?
When it comes to reference notes, the web is unbeatable: it has hyperlinks. Notes are unnecessary for web-based references that can be linked to, but what if you’re referencing a print book with page numbers? Links won’t do the job (yet?). Hyperlinks do, however, make notes on the same page more immediately accessible through same-page anchors (it’s how they’re accessed on this page3), but it’s still somewhat annoying to have to click.
I have an idea or two for notes on web pages that I don’t want to discuss until I can show them. I love using notes as a writer, and love reading them as a reader, so I’d really love to create something that moves the form forward. Until then, keep thinking in tangents and noting it: that’s where the gold is.