Key words and definitions

Question	Answer
Population	A collection of individual items
Sample	Selection of individual members or items from a population
Finite population	A population where you can count the individual members
Infinite population	A population where there are too many members to count
Sampling unit	Individual member of a population
Sampling frame	List of all sampling units, items in a population - a list, map, database etc. (use context)
Statistic	A quantity calculated solely from observations in a sample
Sampling distribution	Gives all possible values of the statistic and the probability of each occuring
Census	Information is obtained from all members of the population
Sample survey	An investigation using a sample
Bias	Anything that occurs when taking a sample which prevents it being representative of the population
Simple Random Sampling	Every member of the population has an equal chance of being selected
Population parameter	Any measurable characteristic of a population

Resource summary

	Created by Elizabeth Carr over 10 years ago