Which is an advantage of secondary data collection?

• A. It can study temporal changes across years.
• B. It cannot be used to examine trends.
• C. It always replaces primary data entirely.
• D. It is never biased.

Answer: (A)

Secondary data provides information that’s already been collected by others, such as government statistics, reports, or previous studies. The big advantage is that it lets you study changes over time because these datasets often include data from many different years. Having that kind of long time series lets you identify trends and observe how variables have shifted across years without having to carry out new surveys or experiments, saving time and resources while giving a broader historical perspective.

The idea that it cannot be used to examine trends isn’t accurate, since trends are exactly what long-running secondary data can reveal. It also doesn’t mean secondary data always replaces primary data; sometimes you need fresh data to answer a new or specific question. And secondary data isn’t guaranteed to be free from bias—there can be limitations based on how and when the data were collected.