Sampling techniques

• Sampling techniques:

  what is the population, target population and sample?

  Population - large group of people

  target population - group that are the focus

  sample - group from the TP who take part
• Types of sampling:

  describe and evaluate random sampling 


  all members of the population have an equal chance of being selected

  random number generator / name out a hat

  + potentially unbias

  ~ may still be unrepresentative

  ~ participants may refuse to take part
• Types of sampling:

  describe and evaluate opportunity sampling 


  selecting anyone who is available and willing

  + easy

  + cheap

  ~ unrepresentative - from one area

  ~ researcher bias
• Types of sampling:

  describe and evaluate volunteer sampling 


  asking people to sign-up

  eg. adverts, social media, payment

  + easy - they come to you

  + participants more engaged- want to be there

  ~ volunteer bias - attract a certain type
• Types of sampling:

  describe and evaluate Systematic sampling 


  Every Nth member of TP is selected

  sampling frame produced so are organised by a characteristic

  + objective

  + no researcher bias

  ~ time consuming and difficult

  ~ may refuse to take part
• Types of sampling:

  Describe and evaluate stratified sampling


  Look at the population —> strata- work out the strata / characteristic % within the population —> random sampling - according to the %, randomly sample your participants from the TP

  + extremely representative

  + generalisation possible

  ~ difficult / time consuming

  ~ complete representation of TP not possible