Katrina Is Interested in Studying the Relationship Between Attention Deficit

Multiple Choice

Katrina is interested in studying the relationship between attention deficit disorder and behavioural problems in schoolchildren,but she believes that the students' socioeconomic statuses may affect her results.She studies two groups of children through an intervention treatment and makes sure that all children in both groups are from homes with the same level of income.What technique does Katrina use in this study?

A) matched samples
B) matched pairs
C) random sampling
D) third-variable correlation