Hello, Science! [03/03/17]

$If pigs can whistle, then horses can fly... or... De Finetti's Theorem$
If pigs can whistle, then horses can fly... or... De Finetti's Theorem

We talked about the concept of exchangeability a few weeks ago. I presented three urn models, two of which defined exchangeable probability distributions. The main idea I wanted to convey using the first and second urn models was that exchangeability is not just independence: urn model 2 does not look exchangeable at first sight b…