In one of the most decisive battles in history, a large Roman army under Valens, the Roman emperor of the East, is defeated by the Visigoths at the Battle of Adrianople in present-day Turkey. Two-thirds of the Roman army, including Emperor Valens himself, were overrun and slaughtered by the mounted barbarians.
Answer:
It generates new insights from previous analyses
Feasibility of both longitudinal and international comparative studies.
It saves time.
DISADVANTAGES
Inappropriateness of the data. Data collected by oneself (primary data) is collected with a concrete idea in mind. Usually to answer a research question or just meet certain objectives this sense, secondary data sources may provide you with vast amount of information, but quantity is not synonymous of appropriateness.
What are the "these" you speak of?
