sample

a group of scores selected from a population.

If you are studying height in adults, there are potentially an infinite number of scores you could collect (in fact, there are about 4 billion scores, the total number of adults on Earth). If you are researching political preferences in voting Americans, there are as many scores as there are Americans eligible to vote. This is known as the population of scores

It would be impractical to collect every single possible score in the population. Luckily, this is usually not necessary. Instead, all that is needed is a sample of scores from the population.

If the scores are chosen or found at random, then the sample is called a random sample. Parameters of the random sample (such as mean and variance) ca