ABSTRACT

A sample of observations is defined as a collection of i nd iv idua l observat ions recorded by a specif ied p rocedure . One i n d i v i d u a l observation is based on a single unit in a biological sense i.e., one rat. However, if we had studied the weight of a single rat over a period of t ime, the sample of i n d i v i d u a l observations w o u l d be the weights recorded of one rat at successive times. If we wish to measure the temperature in a study of ant colonies, when each colony is a basic sampling unit, each temperature reading for one colony is an individual observation, and the sample of observations is the temperature for all the colonies considered. A synonym for individual observation is item.