gobear, your first and third criteria are possibly contradictory in most cases.
Primary sources are good for demonstration of a problem with a group, though the problem would need to be spelled out in some fashion—perhaps in an op-ed article (not likely). Otherwise, most primary sources are definitely biased. I mean: that’s why they are who they are, because they think they are right.
Which isn’t to say they will present the matter unfairly, but rather that it is easier to be skeptical of a primary source talking about themselves.
Third parties make for objectivity, IMO.
As for your second point, op-ed pieces can have factual information in them, though I agree that a different source would be better if only because it should be easier to separate the wheat from the chaff, as it were.
As for your third point, bias is a word people use to smear what they disagree with. Reference my previous comment on this. “If I am right, it is a fact; if they are wrong, and yet they hold their opinion, it is bias.”
Logical arguments, several sources from across the “bias spectrum” (whatever the issue is there are bound to be all sorts of ‘wingers’ for it), and a little wit make the argument. I have never, ever, made such an argument. I accept far less for a valid discussion.
But, my room is also very messy, so this might not apply to everyone.
…
Anyway: valid sources are contextual. I would tend to accept with less skepticism anything done by a panel or other otherwise disparate group of [insert relevant field here] than I would a single article quoting people all over the place. In some cases this is not normal behavior. In these instances, cites become a wild goose chase where a poster attempts to synthesize (at best) the opinions of ‘wingers’ in order to offer an argument.
I don’t think a solid rule can be made about sources. For some things it is easier than others: a debate about legality could run the non-cite gambit with an argument about morality, or it could play out as a debate over inconsistent rulings, in which case cites would crop up from our own legal system. Here an opinion paper or even an article that didn’t specifically mention which case it was wouldn’t impress me at all.
IMO most of the arguments had in GD make “good” citations impossible. The debate is a synthesized opinion from several sources, and if it were so cut-and-dry that someone could just lay down a few links and some symbols from predicate logic then there wouldn’t be anything to debate.
A “good” cite proves your opponent wrong. I think that is what most people look for. When offered a cite in response to their own challenge, they then proceed to demonstrate why this cite is not good and so on.
A cite should, IMO, at most, be used for matters of definition or simple facts not open to severe interpretation (a cite about gun crime statistics, but not a cite about what gun crime statistics means: that’s the damn debate!). Otherwise, well, that’s why we’re here: to debate, not to practice vB coding of hyperlinks. So debate.
Again, MHO.