Sampling and Tests of Significance

Abstract

We must now start to be more rigorous about the use of terminology in describing a distribution by following the accepted conventions. In considering the porosity of a sandstone body there was a population of all possible porosity measurements for that sandstone. Generally a population is a set of measurements (it is the measurements, not the objects) of a specified property of a group of objects. These measurements may be of attributes or of variables. Some people call this population a universe to distinguish it from a biological population which is a sample. It may be an infinite population (every possible measurement of the length of this page) or a bounded population (measurement of the size of every quartz grain in a thin section). Many geological populations can be considered infinite though they are really finite. For example, measurements of the orientation of every felspar phenocryst in a lava, or every pebble on a beach can be thought of as an infinite population.