Yes! You're communicating less information! Well, it could be a good thing, if you noticed an anti-correlation between your no-good-reason opinions and whatever the best-reasons opinion is. But I don't think that would actually be the case.
I would advise something more like "I'm just talking out of my ass here, but it seems like". For results of studies that I can't remember details of I like "don't quote me on this but", for qualitative answers "no bloody idea, but" and for quantitative answers "I'm making this up, but". That way you share both the opinion, and give them a reasonably good picture of how much support for your opinion you have.
If you were dealing with a Bayesian you could just say "I believe x, based on three signals of 5:1 in favour of x". Obviously, this is gibberish to the average person - but a Bayesian would only update their posterior slightly on hearing your weakly-supported opinion, so using such phrases gets average people to only change their minds a little bit; thus being a little bit more like a Bayesian reasoner.
Well, it could be a good thing, if you noticed an anti-correlation between your no-good-reason opinions and whatever the best-reasons opinion is.
It doesn't just depend on the accuracy of the opinions themselves, but rather on how the recipient weighs the information.
If you have a certainty of 55% on a binary (A) or (B) question, and you respond "it seems to me there's a 55% chance of "Yes" ", I wouldn't be surprised if the non-perfect Bayesian recipient of the information would treat this as if you had mentioned a certainty of 75%.
I...
Today's post, "I don't know." was originally published on 21 December 2006. A summary (taken from the LW wiki):
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