Sampling

• What is the term used for the larger group from which a sample is drawn in psychological research?

  Target population
• Why do psychologists need to establish general rules about behavior?


  To create psychological theories
• What is a small group of participants in research called?

  Sample
• What is the relationship between a sample and the target population?


  The sample is drawn from the target population
• Give an example of a target population.


  Teenagers
• What is the aim of generalizing results from a sample?


  To apply findings from the sample to the target population
• What does it mean for a sample to be representative?


  It reflects the characteristics of the target population
• If a sample is not representative, what can be said about the generalization of results?


  The results cannot be reliably generalized to the target population
• What are the key components of establishing a target population in psychological research?


  • Define the target population
  • Draw a sample from this population
  • Ensure the sample is representative
  • Aim to generalize findings to the target population
• What is a population in research?


  A group of people who are the focus of the researcher's interest
• What is a sample in research?


  A group of people who take part in a research population
• What does it mean for a sample to be representative?


  It closely matches the target population in key variables and characteristics
• What is the purpose of generalization in research?


  To apply findings and conclusions broadly to the population
• When can generalization be considered valid?


  When the sample of participants is representative of the target population
• What are the key components of a research population and sample?


  • Population: Focus group of interest
  • Sample: Subset of the population for research
  • Representativeness: Sample matches population characteristics
  • Generalization: Findings can be applied to the broader population
• Random Strengths • Unbiased • It is widely accepted that since each member has the same probability of being selected, there is a reasonable chance of achieving a representative sample (generalised) Weaknesses • Random sampling is difficult and time-consuming to conduct • Representative sample is not guaranteed (could all be male by chance) • Some may refuse to take part
• Systematic Strengths • This sample is objective, once the system has been established the researcher has no influence over who is chosen. • This method offers an unbiased chance of gaining a representative sample. Weaknesses • If the list has been assembled in any other way, bias may be present. Every nth person could be of one gender so cannot be generalised
• Volunteer Strengths • Practical and easy way to gather ppts as it requires minimal input from the researcher. • Less time consuming Weaknesses • Lacks generalisability as those who are willing to give up their time are likely to be differ from target population
• Stratified Strengths • Most representative because it is designed to accurately reflect the composition of the population. This means that generalisation of findings becomes possible. Weaknesses • It takes more time to plan. • Care must be taken to ensure each key characteristic present in the population is selected across strata, otherwise this will design a biased sample. 1,000 students in the school. 300 are 10-12 years old, 500 are 13-15 and 200 are 16-18. Therefore, the subgroup is 30%, 50% and 20%.
• Opportunity Strengths • This method is easy and inexpensive to carry out. • This often achieves a large sample size through reaching a wide audience. Weaknesses • The researcher has complete control over the selection of participants, and may avoid people they do not like the look of (researcher bias) • Findings can be unrepresentative of the target population, e.g a specific street so findings cannot be generalised
• Sampling is the process of selecting a representative group from the population under study.
• Generalisability means the extent to which their findings can be applied to the larger population of which their sample was a part.