sampling methods

• what are the 5 types of sampling methods?

  random, systematic, stratified, opportunity, and volunteering sampling.
• what is random sampling?

  Random sampling is a method of selecting a subset of individuals from a larger population in a way that each individual has an equal chance of being chosen.
• random sampling involves identifying everyone in a target population using a sample frame and select the amount f participants needed.
• what is an advantage to random sampling?

  not biased —> no investigator effects
• what is a disadvantage to random sampling?

  the sample is not representative of different types of people within the sample frame because everyone has an equal chance of being selected.
• what is systematic sampling?

  Sampling method where every nth individual in a population is selected for inclusion in the sample.
• what is an advantage of systematic sampling?

  unbiased as participants are selected using an objective system, researcher has no influence oof who is chosen
• what is a disadvantage of systematic sampling?

  not a good representation of the population
• what is volunteer sampling?

  Non-random sampling method where participants are selected based on their willingness to volunteer.
• what is an advantage of volunteer sampling?

  participants recruit themselves so it is very ethical and convenient for the investigator.
• what is a disadvantage of volunteer sampling?

  it is n unrepresentative sample —> participants will likely be extroverted and motivated (volunteer bias)
• what is stratified sampling?

  Sampling technique where the population is divided into distinct groups or strata, and a random sample is taken from each stratum.
• how would you calculate a strata?

  (total sample size/population size) x layer size
• what is an advantage of stratified sampling?

  free from bias and good representation of the population
• what are the disadvantages of stratified sampling?

  • time consuming
  • wont give a representative sample because all the participants would have shared characteristics
  • vulnerable to bias (investigator effects)