RM- Sampling techniques Flashcards
What is random sampling?
Random sampling is when every member of the target population has the same chance of being selected.
What are advantages of random sampling?
1) If the target population is large and a large sample is drawn, then its likely the sample will be representative and therefore results can be generalised to the target population.
2) No researcher bias as the sample has been chosen by chance without any conscious choice from researcher. Everyone has an equal chance of being selected.
What are disadvantages of random sampling?
1) Sometimes difficult to get full details of a target population. For example, they might be in prison or not registered.
2) Not all members of the target population who are selected to take part will be available or willing to take part, making the same unrepresentative.
What is systematic sampling?
It is a sampling strategy where pps are selected by taking every Nth person from a list.
What are advantages of systematic sampling?
1) Far simpler than random sampling as it only requires a list of target population. It also requires less time and effort compared to random sampling.
What are disadvantages of systematic sampling?
1) Not all members of the target population who are selected to take part will be available or willing to take part, making the same unrepresentative.
What is stratified sampling?
- Stratified sampling involves classifying the population into categories and randomly choosing a sample.
- The population are divided into strata in terms of characteristics e.g age, gender
What are advantages of stratified sampling?
1) All groups within a population are included, therefore the sample should be representative of the population.
What are disadvantages of stratified sampling?
1) It can be very time consuming as the categories have to be identified and calculated.
What is opportunity sampling?
Involves selecting participants who are readily available and able to take part.
What are advantages of opportunity sampling?
1) Easiest and most practical method of ensuring large samples.
What are disadvantages of opportunity sampling?
1) There is a high chance that sample will not be representative of target population.
What is volunteer sampling?
Involves people volunteering to participate in a study.
What are advantages of volunteer sampling?
1) This method saves the research time and effort as the participants would come to them and volunteer their time and involvement.
What are disadvantages of volunteer sampling?
1) A certain type of person tends to volunteer (enthusiastic, interested) and this means that there is a very high chance the sample obtained is unrepresentative and will not accurately reflect the target population (volunteer bias).
