types of sampling

• random sampling (SAMPLING FRAME)

  • selecting from the sample frame at random
  • everyone has an equal chance at being selected
• systematic sampling (SAMPLING FRAME)

  • selecting from the sampling frame at regular intervals
  • can be biased if there's a hidden pattern in the population
• stratified sampling (SAMPLING FRAME)

  • dividing sampling frame into subgroups
  • ensures the sample is representative of population in terms of important characteristics
• volunteered sample (NO SAMPLING FRAME)

  • PPs volunteer as part of study
  • cost effective for recruiting
  • may lead to biased results
• opportunity sampling (NO SAMPLING FRAME)

  • researchers go to a place and ask people if they would like to participate
  • convenient
  • results might not be representative of TP
• purposive sampling (NO SAMPLING FRAME)

  • researchers choose PPs based on characteristics relevant to research
  • may lack diversity
  • may not represent TP
• snowball sampling (NO SAMPLING FRAME)

  • PPs nominate other PPs to take part creating a 'snowball' effect
  • helpful for researching hard to reach populations
  • may not be representative of TP
• what is a sampling frame?

  a list of individuals who could take part in a study