Part of the idea behind the introduction is to replace an early series of posts: "Statistical Bias", "Inductive Bias", and Priors as Mathematical Objects. These get alluded to various times later in the sequences, and the posts 'An Especially Elegant Evolutionary Psychology Project', 'Where Recursive Justification Hits Bottom', and 'No Universally Compelling Arguments' all call back to the urn example. That said, I do think a more interesting example (whether or not it's more 'ordinary' and everyday) would be a better note to start the book on.

Do feel free to send stylistic or substantive change ideas to errata@intelligence.org, not just spelling errors.