_____ includes data collected for another purpose (for example, census data).

• A. Secondary Data
• B. Primary Data
• C. Tertiary Data
• D. Qualitative Data

Answer: (A)

Secondary data are data collected by someone else for a purpose other than your current study, such as census data. The census is gathered to describe the population at large, not to answer a specific research question you have today, so it’s a prime example of data you can reuse for new analyses. Using secondary data can save time and resources compared with collecting new data yourself (primary data). However, there may be mismatches between how the data were collected and what you want to study, including differences in variable definitions, measurement methods, timing, and population coverage. Tertiary data are summaries of primary sources, and qualitative data refer to nonnumeric information that can be part of either type but do not by themselves define data collected for another purpose.