strengths longitudinal + weaknesses crossectional (3+3)

• Strengths of Longitudinal Studies

  
  

  One major strength of longitudinal studies is that they control for participant variables, as the same individuals are studied over time. This means that differences in results are more likely due to development or experience rather than individual differences. This repeated measures design increases internal validity.

  Additionally, they allow researchers to track changes and patterns over time, making them ideal for studying development or the long-term effects of variables such as early childhood experiences.

  Finally, by using the same participants, longitudinal studies can highlight cause-and-effect relationships more accurately than designs comparing different groups.
• Weaknesses of Cross-Sectional Studies

  A key weakness of cross-sectional studies is that they involve comparing different individuals, meaning that any differences found may be due to participant variables rather than the independent variable, reducing internal validity.

  There is also a risk of cohort effects, where individuals in different age groups (cohorts) may differ due to shared experiences rather than age—for example, older participants might have had poorer education or diet.

  Lastly, while they are quicker and cheaper, cross-sectional studies cannot track development over time, so they may miss important changes that a longitudinal approach would capture.