Types of sampling

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Created by
Iris Scotford

Cards (5)

  • Random Sampling 

    A list of members of target population are allocated numbers manulally. Use a random number generator to to choose number of PP in sample.
    +unbias sample as members have an equal chance of being chosen and is likely to be representative. Removes bias during selection process
    -very time consuming as names of all TP must be obtained and all PP must be assigned a number.
    -could produce a bias sample
  • Systematic sampling 

    A number is chosen using a random number generator. Researcher gives each person a number by using a set of techniques. Then from each group a person is selected every nth person.
    +un bias as all members of TP have an equal chance of being selected so representative can be generalise findings.
    +randomisation removes researcher bias during selection process.
    -not suitable when there is no list of TP.
    -not truly free from bias unless is chosen at random.
  • Stratified sampling 

    Subgroups are identified within the TP and a proportionate number of each group is randomly obtained.
    +higher representative of TP as subgroups are included in sample in same proportion.
    +Allows findings to be generalised
    -very time consuming to find subgroups
    -its more expensive
  • Opportunity sampling 

    Sample is obtained for convince of researcher but still must meet the criteria of TP and it's whoever is available and willing to take part.
    +less time consuming to obtain the sample so less likely to eat into researchers budget.
    -bias sample as the people who meet the criteria and are willing to take part have similar characteristics so not representative of TP so caution should be applied when generalising any findings from sample to wider TP.
  • Volunteer Sampling 

    PP select themselves to take part in a research study, usually by responding to an advert that requests PP and who meet a specific criteria.
    +gives a variety of p0otential PP so less bias than using other methods.
    +quick cheap sample to obtain
    -bias sample as who volunteer are likely to have a similar characteristics.
    -will be issues with generalisation of findings.