Selection of Participants

• Opportunity sample


  A sample of participants produced by selecting people who are most easily available at the time of the study.
• Random sample


  A sample of participants produced by using a random technique so that every member of the target population has an equal chance of being selected
• Sampling


  The method used to select participants for a study. Sampling also refers to the method of recording behaviours in an observation such as event or time sampling. (See also sampling of participants).
• Stratified sample


  A sample of participants produced by identifying subgroups and selecting participants randomly from these subgroups, in the same proportion as their occurrence in the population.
• Systematic sample

  A sample obtained by selecting every nth person (where n is a number).
• Volunteer sample


  A sample of participants that relies on self-selected volunteers.