Sample

A sample is a group of people, objects, etc taken as being representative of a larger group (the population). When studying a sample, the interest is to make inferences about the population at large. Inferential statistics are commonly used for helping make such inferences.

Types of sample

Convenient sample - a sample collected in a manner that is convenient to the researcher, such as students that happen to attend a class, or shoppers who happen to be in a particular shopping center at the time of data collection. Convenient samples may be adequate when carrying out exploratory research, but are considered inadequate when doing confirmatory research, unless other controls, such as random allocation to groups in an experiment, are used.