April 6, 2003
Quote of the day
...the preceding definitions and examples identify four of the five elements of an inferential statistical problem: a population, one or more variables of interest, a sample, and an inference. But making an inference is only part of the story. We also need to know its reliability - that is, how good an inference is. The only way we can be certain that an inference about a population is correct is to include the entire population in our sample. However, because of resource constraints (i.e., insufficient time and/or money), we usually can't work with whole populations, so we base our inferences on just a portion of the population (a sample). Thus, we introduce an element of uncertainty into our inferences. Consequently, whenever possible, it is important to determine and report the reliability of each inference made. Reliability, then, is the fifth element of inferential statistical problems.
The measure of reliability that accompanies an inference separates the science of statistics from the art of fortune-telling. A palm reader, like a statistician, may example a sample (your hand) and make inferences about the population (your life). However, unlike statistical inferences, the palm reader's inferences include no measure of reliability.
Statistics (9th Edition)
James T. McClave and Terry Sincich
page 7
