Evaluation

• Evaluate good external validity

  • Carried out in families’ own home
  • Most observations done by parents.
  • Behaviour of babies less likely to Be affected by presence of observers.
  • Natural behaviour
• evaluate longitudinal design

  • same children followed up and observed regularly
  • alternative - cross-sectional design which would observer different children at each age.
  • longitudinal has better internal validity because they dont have confounding variables of individual differences
• what are confounding variables?

  an extraneous variables that affect both IV and DV, potentially creating a false causal relationship
• Evaluate a limited sample characteristics

  • All families from same district and social class in same city and at a time over 50 years ago.
  • All from Glasgow and majority were working class.
  • Child-rearing practices vary across cultures ad historical periods.
  • Results don’t generalise to other social and historical contexts