Last week I received my daughter's last college tuition bill. When I started writing this blog, she had not yet graduated from high school -- can it be?  I looked at the tuition bill with a mixture of anxiety and gratitude.

When I teach statistics, I often point out that some values we calculate have different notation depending on whether they are calculated from the entire population or a from a sample taken from that population, even if the calculations are identical in the different situations. I explain this to my students by telling them a woman’s name, and asking them if they know who that woman is. They almost always have no idea who she is.