Sampling

• Sample: A group of people who take part in a study
• Participant: The individuals who are part of the sample
• Why is sampling important?

  It is important to use suitable participants in your study so that your results can be generalised.
• Sampling: The method used to select participants such as random, opportunity and volunteer
• Generalisation is the extent to which findings can be broadly applied to the population. This is possible if the sample of p’s is representative of the target population
• Populations and Sampling:

  The sample is taken from a larger group of people whose behaviour you are interested in studying. This larger group of people is known as the target population.

  For example if you were interested in studying AS students in Sixth Form Colleges in Oxford this would be the target population.
• Populations and Sampling

  Ideally the sample should reflect the characteristics of the target population so therefore you would use sampling techniques to choose people who represent the target population.
• Opportunity sampling

  is the sampling technique most used by psychology students. It consists of taking the sample from people who are available at the time the study is carried out and fit the criteria you are looking for.
• Random Sampling

  is a sampling technique in which every member of the population has an equal chance of being chosen.
• Random sampling:

  There are various techniques that can be used to obtain a random sample:

  • The lottery method
  • Random number table (every person given a number)
  • Random number generator (every person given a number and using Microsoft Excel type =RAND(100) to get a random number between 1-100)
• Stratified sampling

  involves identifying the subgroups in the target population and then choosing a sample which consists of participants from each category in the same proportions as they are in the population
• Systematic sampling

  is where the researcher chooses every nth member of the target population.

  So they may choose every 3rd person in the target population.
• Volunteer Sampling

  • is when participants volunteer themselves
  • e.g. by responding to an advertisement in the newspaper
• Stratified Sampling

  • First to create a stratified sample we analyse the different subgroups in our target population.
  • From this we understand how many participants from each subgroup we need in our sample (to make it stratified).
  • How I would select my actual sample is through random sampling techniques