Cross-sectional research: In cross-sectional research, the experimenter or the researcher examines a group of people, specific context, and a social phenomenon with the help of a sample. The cross sectional-study or research is also known as transverse study, prevalence study, etc. This is a type of an observational study, that examines a particular population data in a specific time.
Advantage:
1. Cost-effective
2. Easy to gather and assess data.
3. Less time taking.
In the give question, Dr Cross is studying the relationship between age and dependency/independence using cross-sectional research.