AO3 - Van Ijzendoorn

• Comparisons in Van Ijzendoorn is aided by the standardised methodology of the 32 studies, which adds to the reliability of the findings.
• The strange situation is a standardised method, in a controlled environment, so has high internal validity.
• The study was not globally representative as many countries were not represented, this limits the generalisation.
• Many of the studies used were biased to western society which makes them ethnocentric.
• Confounding variables can play a part in research from meta-analyses.
• There is no knowledge that levels of control were consistent across the 32 studies, which lowers the reliability.