Sampling Methods

Question 0

Random sampling

The sample is selected by picking names out of a hat (or with a computer) - like the National Lottery balls.

Answer 0

Strengths - There is no researcher bias in who is selected and everyone stands an equal chance of being selected. It is also quick and easy.
Weaknesses - The sample may not be representative of the whole population.

Question 1

Stratified sampling

This involves picking people from different groups within the population (eg. different genders, ethnicities, ages, social classes).

Answer 1

Strengths - The sample will be representative and give the point of view of all the different groups in the population.
Weaknesses - Time-consuming to select the sample than other sampling methods.

Question 2

Quota Sampling

The researcher picks participants until they have the number they need (ie their ‘quota’).

Answer 2

Strengths - Quick and easy to select the right sort of people for the research.

Weaknesses - The sample is likely to be biased because the researchers choosing the participants.

Question 3

Systematic Sampling

The researcher uses a system to pick the participants (eg. every 10th name on the register).

Answer 3

Strengths - The participants will be a cross-section of the population, so will hopefully be representative.

Weaknesses - only the people on the register stand a chance of being selected.

Question 4

Snowball Sampling

The researcher select some person, then asks them to put them in touch with other people, etc.

Answer 4

Strengths - Useful for researching hard to contact groups eg. Gangs.

Weaknesses - Very time-consuming, so only small samples are used and the results are not generalise-able.