Non-Representative Sampling

• Non-representative sample


  A sample that is not typical of the wider population
• Non-representative sampling methods

  • Opportunity/Convenience Sampling
  • Purposive/Judgemental Sampling
  • Snowball Sampling
  • Volunteer Sampling
• Opportunity/Convenience Sampling


  The researcher stops whoever they come into contact with. This is often used by students or as a pilot study. Because of the basic nature of the sample, it is rarely used beyond the pilot stage.
• Opportunity/Convenience Sampling


  • University students using a convenience sample for a dissertation on the 'dual burden' carried out by women
• Opportunity/Convenience Sampling

  • Practical strength: can be useful at pilot study stage to assess questionnaire, interview technique etc.
  • Practical strength: no sample frame needed and it is a quick and easy sample method to use due to little restrictions and effort required
  • Ethical strength: informed consent, those who agree to participate will agree to do so
• Opportunity/Convenience Sampling

  • Practical limitation: the researcher may not be able to gather a full sample
  • Ethical limitation: the researcher pressure, some people may feel more pressured to take part if asked face-to-face
  • Theoretical limitation: it is not random and is subject to bias as the sample is selected by the researcher, impacting the representation, therefore it is unrepresentative of the wider population
• Purposive/Judgemental Sampling


  The subjects are selected because of some social characteristic they possess. Hence there is a target population under study.
• Purposive/Judgemental Sampling


  • Willis' 'Learning to Labour' study
• Purposive/Judgemental Sampling


  • Practical strength: it is quick to use as the researcher simply targets the required population
  • Ethical strength: a person can consent to the research as they have been selected
  • Theoretical strength: it targets a particular desired group hence it should only contain relevant populations for the study increasing validity
• Purposive/Judgemental Sampling


  • Practical limitation: the researcher may not be able to gather a full sample therefore the researcher can exclude wider society, ignoring all individuals
  • Ethical limitation: whether the researcher may be put in any harm gathering such a sample, especially when studying extreme or deviant cases
  • Theoretical limitation: there is no guarantee that the actual population chosen actually represents others in the chosen group hence it runs the risk of not being representative
• Snowball Sampling


  The researcher makes a connection with one participant, who then introduces them to more, thereby growing the sample. It tends to be used by qualitative researchers because it offers the chance to study deviant groups in some depth.
• Snowball Sampling


  • Patrick's 'Glasgow Gang' study
• Snowball Sampling


  • Practical strength: no sample frame is needed and they are very useful to gain access to certain deviant groups especially those less accessible like criminals and religious cult members
  • Ethical strength: participants are willing to take part, giving informed consent, and may be more comfortable being approached by someone they already know
  • Theoretical strength: when access is established you access those you need to access for the purpose of the research increasing the representation
• Snowball Sampling


  • Practical limitation: it is difficult and time-consuming to collect sample through others
  • Ethical limitation: the loss of control the researcher has once they pass on the sample - how does the researcher know whether the participants are legitimate? It may also raise further ethical issues such as access to criminals and being undercover
  • Theoretical limitation: loss of control as being reliant on others to gain a sample and so can be unrepresentative
• Volunteer Sampling


  The researcher asked for people to volunteer to be studied, hence the sample is self-selected.
• Volunteer Sampling


  • Hite's 'Women and Love' study
• Volunteer Sampling


  • Practical strength: no sample frame is needed and therefore it is easy to find a sample group
  • Ethical strength: those who participate have volunteered to do so, therefore giving their full informed consent
  • Theoretical strength: there are willing participants which should mean a high response rate, therefore increasing the likelihood of representativeness
• Volunteer Sampling


  • Practical limitation: numbers cannot be guaranteed and it can exclude wider society depending on when and where research is completed
  • Ethical limitation: pressure, people may find it difficult to say no the researcher if asked in person and experience researcher pressure
  • Theoretical limitation: those who volunteer may be unrepresentative of the wider population, they may have a particular "agenda" or be "typical"
• favoured by interpretivists who value understanding of individuals rather than making their studies generalisable