Dr. austin is studying the effects of aging on memory. she gives a test of memory to a group of 20-year-olds, a group of 30-year-olds, and a group of 40-year-olds. then she examines the data for significant differences between the age groups. which research design is dr. austin using?

Cross-sequential.

Explanation:

Cross sequential study may be defined as a type of research method that are used by combining the cross sectional design and longitudinal design. This aim is to minimize the problems.

As Dr. Austin studies the effects of aging on memory. The doctor needs long time to study this effect. The one factor can be taken as longitudinal design and other as cross sectional design. This signifies that the doctor has used the cross sequential based research method.

Thus, the answer is cross- sequential.