Over the course of 2013, I read about a gross of books (probably equally distributed among the platforms of published paper, yet-to-be-published paper galley, ebook [both Kindle and iBook], and with my ears). It was a relatively light reading year for me and I even had several opportunities to make selections based on purely personal grounds (It's the "purely" in there that is unusual for me). However, as December 31 rolled into January 1, I could pronounce the hands down "winner" in my reading year: Samuel Arbesman's The Half-life of Facts  enlightens me daily, even though I gobbled it up months ago.
Arbesman, a scientist, walks readers through a wholly accessible and skillfully scaffolded exploration of how we retain "facts" long past their due date, or information about their debunking spreads. This "half-life" is personal, with variance from person to person, and cultural. Especially as adults of iddle age, we know what we know. But we also tend to have formed rigorous beliefs about knowing that we know. Do you know full well that Pluto isn't a planet, and yet "feel" as though "really" it is?
Applying this to the library, and to people who use the library: Do we know that we know what is important that we provide them? And applying this to the library, and the people who work in the library: Do we know that they know what is expected that they know in order to provide the community what is important? In Infopeople's Core Reference Fundamentals course, I am lucky to have the opportunity to discuss basic library tenets straight on twice a year, with cohorts of 50-75 library people in all stages of career and all ages of adulthood. This allows me to see the half-lives of a whole smorgasbord of facts--both arising from the group and in my own initial takes on the assertions of one member or another in the group. Some participants work in libraries where the outmoded "fact" that public internet access is "extra" and beyond what a community information and cultural resource needs to provide. Some are sure of the "fact" that homeless people are by definition behavior problems, a "fact" of a little "fact" nest: to be homeless is to be mentally ill and to be mentally ill is to exhibit disruptive behavior.
Of course, when it's asserted that way, the logical fallacies get up on their tap shoes and dance. And that is part of Arbesman's message: sometims, just by pausing to investigate logically, we can see where the "fact" leaves off and the belief begins.
And sometimes, we need to remember to ask ourselves: am I sure that I'm making this decision with factual information, or am I relying on the half-life of a fact that has been debunked?