Sampling techniques

• What is the target population in research?

  The people a sample is supposed to represent
• What is a sample in research?

  A group used in research that represents a target population
• What is a sampling technique?

  A method used for gathering the sample
• How does random sampling work?

  Every person in the target population has a chance of being in the sample
• What is an example of random sampling?

  All names of the target population are entered into a computer system to generate a sample
• What are the advantages of random sampling?

  There is no bias in the selection of the sample
• What are the disadvantages of random sampling?

  People could say no to taking part, making it time-consuming
• What is opportunity sampling?

  The sample consists of people from the target population who are available
• How does opportunity sampling work in practice?

  The researcher approaches people and asks them to take part in a study
• What are the advantages of opportunity sampling?

  It is easier than methods such as random or stratified sampling
• What are the disadvantages of opportunity sampling?

  The sample may not be representative of the target population
• What is systematic sampling?

  A predetermined system is used to select participants
• How is systematic sampling typically conducted?

  Every fifth person is chosen from a list
• What are the advantages of systematic sampling?

  It is not affected by researcher bias or choice of participants
• What are the disadvantages of systematic sampling?

  The sample may be unrepresentative if every Nth person has similar traits
• What is stratified sampling?

  Subgroups within a population are identified and participants are obtained from each stratum in proportion to the target population
• How does stratified sampling ensure representation?

  Participants are obtained from each stratum in proportion to the target population
• What is an example of stratified sampling?

  If a class has 18 males and 2 females, a sample of 10 would need to consist of 9 males and 1 female
• What are the advantages of stratified sampling?

  It is not affected by researcher bias, and the sample is likely to be representative
• What are the disadvantages of stratified sampling?

  Ensuring that the subgroups in the target population are all accurately identified is difficult and time-consuming
• What is volunteer sampling?

  Participants self-select to take part in a study by either volunteering when asked or by responding to an advert
• How does volunteer sampling work in practice?

  Participants may respond to an advert, such as a poster in a café
• What are the advantages of volunteer sampling?

  It is an easier and quicker method than random or stratified sampling
• What are the disadvantages of volunteer sampling?

  The sample may not be representative, as only certain types of people may volunteer