Beliefs, prejudices and data

When you see a bunch of things moving around in a flock on a pond in the distance, making quacking sounds, and occasionally becoming airborne, you do not ask for DNA evidence to determine that they are ducks, because you already have a lot of background information about swimming ducks. If someone told you they [...]

No mean average-be careful of averages in indicators

People—and businesses—use averages all the time to measure performance.  Consciously or not, we use averages to make inferences about some underlying property of a population. For example, if Pine Crest School has higher averages than River Bank School, we infer that the “typical” student from Pine Crest is better than the typical student from River [...]