It has often been asked if one is a prime number, or if there was a time when most mathematicians thought one was prime. Whether or not the number one is prime is simply a matter of definition, but… Expand

In a cluster-randomized experiment, treatment is assigned to clusters of individual units of interest‐households, classrooms, villages, etc.‐instead of the units themselves. The number of clusters… Expand

What is the first prime? It seems that the number two should be the obvious answer, and today it is, but it was not always so. There were times when and mathematicians for whom the numbers one and… Expand

The way mathematicians have viewed the number one (unity, the monad) has changed throughout the years. Most of the early Greeks did not view one as a number, but rather as the origin, or generator,… Expand