I love reading about nutrition so I just happened to read several articles about K2 which prompted me to look at the relevant research. K2 is pretty big in ketogenic circles, so there's quite a bit of content written about it, although I do not subscribe to ketogenic diet theory at all.

Part of my research involves reading impressions and reviews posted online. I take it all with a grain of salt, of course, but as long as you label it as low quality data, it still has value. Sometimes it matches up with research. In the case of the effect on dental plaque, I could not find any research backing it up, so I discarded it as a fact but I was still aware of it; later, when I observed the benefit in my own experience, knowing that others reported the same thing helped me determine that it was in fact the K2 that did it (and then I knew to re-test K2 to confirm it).