This is a tough one. I don't know how to identify questionable journalism other than by a smell test, either. There are clear risks to vaccines, varying by product. Surely there are risks not yet documented, as well. I think that this could be an extraordinary education in research and critical thinking for the lad, but I can only see it being done piecemeal -- debunking extraordinary or unfounded claims by comparing the diverging views one issue at a time, and anlayzing the sources: their motives, as Amos said, and then the quality of the research evidence discussed. After a while one would build up a resistance to (or bias against) certain types of literature (such as trade rags.)

But if it pits you against his Dad, well, maybe you had just better teach him research and critical thinking in other (less charged) subject areas first, and hope that he learns to apply it in all of his thinking. He's had his shots for the most part anyway, hasn't he?

I thought this was a semantic thread about the word "factoid," which would imply something like a fact, therefore not being fact at all. I always say "factlet" for that reason.