قسمت دوم
3. Controls can be individually matched or frequency matched
INDIVIDUAL MATCHING: search for one (or more) controls who have the required MATCHING CRITERIA. PAIRED or TRIPLET MATCHING is when there is one or two controls individually matched to each case.
FREQUENCY MATCHING: select a population of controls such that the overall characteristics of the group match the overall characteristics of the cases. e.g. if 15% of cases are under age 20, 15% of the controls are also.
تو این مورد از همسان سازی فردی و فراوانی صحبت شده که واضح هست