If a psychologist wanted to compare 6-year-old and 10-year-old children on recognition memory performance, the psychologist would use the method of data collection.

The psychologist would use the cross sectional method. Is a method of which the researcher uses subjects in the same time and uses these subjects for his or her research in which they compare them to obtain results. It could be seen above as the psychologist has two children who are needed to be compared in the same time. That is why it is considered that he or she uses the cross sectional method.