Question

_________ studies are useful to developmental researchers interested in aging as they are not as confounded with cohort, time of study, or historical effects as are other methods.

Answer 1

The answer is longitudinal.

Step-by-step explanation:

Longitudinal studies examine the same subjects over different periods of time. Although it's usually observational (as in the study of aging), it is sometimes used for experimental research.

This type of study is often used in psychology and sociology to observe changes in people's behaviour.