S2 Key Words

Population - A collection of individual items or people.

Sampling frame - A list of all individual members of a populaton.

Sampling Unit - One individual member of the population.

Statistic - A quantity calculated from the observations of a sample with no unknown parameter.

Sampling Distribution - A distribution of all possible values of a statistic and the probability of obtaining it.

Sample Survey -

• Cheaper than a census
• Advantageous when testing items results in their destruction eg. testing the lifetime of a light bulb
• Data is more readily available
•  Natural variation generates uncertainty (disadvatage)
• Can be biased, not truly representative of the population (disdavantage)