How to Measure Anything

If you randomly select one sample out of a large population, even a population that numbers thousands or millions, where you initially believed the population proportion can be anything between 0% and 100%, there is a 75% chance that the characteristic you observe in that sample is the same as the majority.

There is a 93.75% chance that the median of a population is between the smallest and largest values in any random sample of five from that population.

Randi has run into retroactive excuses to explain failures to demonstrate paranormal skills so often that he has added another small demonstration to his tests. Prior to taking the test, Randi has subjects sign an affidavit stating that they agreed to the conditions of the test, that they would later offer no objections to the test, and that, in fact, they expected to do well under the stated conditions.