Longitudinal studies

• What is a longitudinal study?


  A study that observes a group of individuals over an extended period of time
• What is the primary purpose of longitudinal studies?


  To see if changes occur in participants over time
• How long can longitudinal studies last?


  Several decades
• What are the advantages of longitudinal studies?


  • Allows researchers to look at changes over time
  • Provides in-depth knowledge of participants
  • Controls participant variables
• What are the disadvantages of longitudinal studies?


  • Require enormous amounts of time and are often expensive
  • Typically involve a small group of subjects
  • Participants may drop out, causing attrition
• Why is it difficult to apply the results of longitudinal studies to a larger population?


  Because they often have only a small group of subjects
• What is participant attrition in longitudinal studies?


  When participants drop out of the study, reducing the sample size
• In what areas are longitudinal studies particularly useful?


  When studying development and life span issues
• How do different methods in longitudinal studies ensure validity?


  • Strengths of one method counteract weaknesses of another
  • Provides a more comprehensive understanding of the research topic