IB Math Apps: Sampling Methods. definitions & examples

simple random sampling definition

every possible sample (of a given size) has an equal chance of being selected. Need a list of entire population.

Convenience sampling definition

respondents are chosen based upon their availability. does not produce random sample.

Systematic sampling definition

participants are taken at regular intervals from a list of the population.

Stratified sampling definition

the population is split into groups based on factors relevant to the research, them a random sample from each group is taken in proportion to the size of that group. Produces a sample representative of the population over the factors identified.

Quota sampling definition

the population is split into groups based on factors relevant to the research, the convenience sampling from each group is used until a required number of participants are found.

simple random sampling example

Selecting members of a population out of a hat.

systematic sampling example

select some starting point and then select every fifth element in the population

convenience sampling example

create a sample by only choosing your classmates from grade 11.

stratified random sampling example

Population divided into if they wear glasses. There are 10 individuals who wear glasses and 25 who do not wear glasses. You choose 2 individuals who wears glass and 5 individuals who do not wear glasses at random.

quota sampling example

Population divided into if they wear glasses. There are 10 individuals who wear glasses and 25 who do not wear glasses. You choose 2 individuals of each group.