Yesterday I finished transcribing "The Ups and Downs of the Hope Function In a Fruitless Search". This is a statistics & psychology paper describing a simple probabilistic search problem and the sheer difficulty subjects have in producing the correct Bayesian answer. Besides providing a great but simple illustration of the mind projection fallacy in action, the simple search problem maps onto a number of forecasting problems: the problem may be looking in a desk for a letter that may not be there, but we could also look at a problem in which we check every year for the creation of AI and ask how our beliefs change over time - which turns out to defuse a common scoffing criticism of past technological forecasting. (This last problem was why I went back and used it, after I first read of it.)

The math is all simple - arithmetic and one application of Bayes's law - so I think all LWers can enjoy it, and it has amusing examples to analyze. I have also taken the trouble to annotate it with Wikipedia links, relevant materials, and many PDF links (some jailbroken just for this transcript). I hope everyone finds it as interesting as I did.

I thank John Salvatier for doing the ILL request which got me a scan of this book chapter.

I suspect that achieving a clear mental picture of the sheer depth and breadth of the mind projection fallacy is a powerful mental tool. It's hard for me to state this in clearer terms, though, because I don't have a wide collection of good examples of the mind projection fallacy.

In a discussion yesterday, we all had trouble finding actual example of the mind projection fallacy. Overall, we had essentially two examples:

• Taste. People frequently confuse "I like this" and "this is good." (This really subsumes the attractiveness example.)
• Probability. This seems like a pretty good just-so-story for where frequentist probability comes from, as opposed to Bayesian probability.

Searching for "mind projection fallacy" on Less Wrong, I also see:

• Thinking that purpose is an inherent property of something, instead of it having been placed there by someone for some reason. (here)
• Mulling or arguing over definitions to solve object-level problems. (actually, most the ways words can be wrong sequence)

Imagine I'm trying to explain the mind projection fallacy to someone, and giving a handful of sharp, clear examples before explaining the general principle. What are some examples I could use? (I really want to explain it more sharply to myself, but also to members of my meetup.)