Research methods sampling

• What are sampling methods?

  Method by which a group of participants are selected to take part in a study, must be representative of target population
• What is random sampling and what is an example of it?

  Random means each member of the population has an equal chance of being selected, names put in a hat pulling out total number required for the sample
• What is the advantage of random sampling?

  Unbiased - each person has an equal chance of being selected
• What is the disadvantage of random sampling?

  selecting randomly can be difficult and time consuming as you have to get list of the TP first
• What is opportunity sampling and whats an example of it?


  Using those avaliable at the time of sampling, for example those walking past on a street
• What is an advantage of opportunity sampling?

  Easy and quick, no prior preparation
• What is a disadvantage of opportunity sampling?

  certain subgroups within the TP may not be avaliable at the time of testing
• What is volunteer sampling?

  Placing an advertisement and using participants that volunteer themselves to take part
• What is an advantage of volunteer sampling?

  quick, easy and doesn't require much effort as pp's volunteer themselves
• What is a disadvantage of volunteer sampling?

  Biased as only helpful motivated people may reply = volunteer bias
• What is stratified sampling?

  Different subgroups in population are identified, pp's selected by a random sample from each subgroup in proportion to their occurance in the TP
• What is an advantage of Stratified Sampling?

  most representative method as there are equal proportions of randomly selected ppl from each subgroup
• What is a disadvantage of stratfied sampling?

  Identifying TP subgroups and selecting randomly can be time consuming and difficult
• What is systematic sampling and what is an example of this?

  Generating a list of all members in the TP and using a system to pick participants for example the first 3 ppl in the register
• What is an advantage of systematic sampling?

  unbiased, using a predetermined system which is decided on before beginning to select the sample
• What is a dsadvantage of systematic sampling?

  Those selected may not want to take part so sample could be affected