Nassim Taleb? If I were to organize a science fair for grade-schoolers, I'd do such experiments in coin-tossing and urn-balling. But I'd focus on *statistics* vs. *probability*, to try to show how statistics can provide insight on probabilities, but only after a sufficiently large number of experiments have been averaged together. Thus, I'd have the students go through & accumulate the results of experiments, so they could see for themselves how many experiments are required before the statistics give a decent approximation to the probability model. This insight should be a *required* part of mathematical training, *prior* to doing any "scientific" experiments, because the student has to understand the limitations of the experimental process itself, before starting to believe any results from such experiments. At 12:53 AM 3/25/2017, Cris Moore wrote:

Is there a good source for intro-level probability "paradoxes" that would give me an opportunity to pit cognitive biases against mathematical level-headedness?

I have in mind things suitable for e.g. 6th-graders, things like:

"I flip 8 coins. Which is more likely, that they come up HTTHHTTT or HHHHHHHH?"

- Cris