So, just because a person is debating something on Internet, it is still a reasonable for other participants to expect that other participants provide citations, links, or evidence to back up one's argument.
In various forums in which people are disagreeing, I often see commenters make huge, sweeping claims about "what the research shows" and how "most people agree that" and that "it's just common sense."
A few weeks ago, for instance, one guy I was debating with quoted almost verbatim from a Wikipedia article, without linking to it or citing it, while acting as though he were commenting off-the-cuff from his own Extensive Body of Knowledge About The Research. When pressed for supporting evidence for his claims,
this Just-Telling-It-Like-It-Is Guy responded with a
snarky and huffy retort along the lines of, "This is just a blog, geez, what do you expect MLA or
Like, dude makes a buncha claims about the purported body of research, but it's So Unfair to ask him which specific studies he's referring to?
And, readers, are you too familiar with the, "well, the studies are out there, if you just google them" trick, whereby commenters wipe their hands from doing actual work and instead shifting that burden to others to do their research, consolidate the findings, and develop their argument on top of rebutting it.
I've also seen others respond to a request for citations by "joking" that it's so unfair of me have asked them to practically produce a 100-page dissertation in blog comment form, or to write a scholarly article fit for publication and peer review, by merely asking them to direct me to a supporting study or two. Oh yes, they have time to make Big Conclusions, but they don't have time to develop supporting arguments for those conclusions.
It's such an interesting and exaggerated response.
To me, it comes off as laziness, self-centeredness, and/or illusory superiority. It's as though their arguments are so self-evidently correct to these commenters that they cannot fathom that other people require more proof than "because I said so" or "I think about this a whole bunch."
So, here is my suggestion to facilitate the process of Providing Supporting Evidence For Sweeping Claims:
APA, MLA, Bluebook, or other formal citation methods are not necessary for blog commenting purposes. These citation methods exist in a context, and blog commenting is not usually an academic context in which these methods are required.
However, it's also been my experience that people, if they are fair, will often grant deference to one's blog comment in direct proportion to the amount of thoughtfulness that it looks like someone put into crafting the comment. That is why drive-by one-liners and "because I said so" comments do not tend to embiggen the discourse.
Many blog commenting systems contain a hyperlink button that allows one
to easily embed a link to a source. Use of that mechanism will, in my opinion, suffice as far as "citation methods" go.
And, because how a link is relevant to one's position, comment, or argument is also not usually self-evidently clear, it is also reasonable for other conversation participants to request some additional clarifying commentary on the part of the person linking to another source.