What are the key differences between primary data and secondary data as described in the chapter?

Primary data are original data collected specifically for a study, providing direct access to the research process without additional interpretations. Secondary data are pre-existing data used for new analyses, which may introduce biases due to previous interpretations.

Primary data, also known as novel data, are collected directly through the conduct of an original study. This type of data provides firsthand information that is specific to the research questions being investigated, ensuring that the data are directly relevant and unaltered by previous analyses. In contrast, secondary data, or accessible data, are derived from existing sources such as previous studies, databases, or records. These data have already been collected and interpreted by others, which can introduce biases or limitations due to the context in which they were originally gathered. Secondary data are often used for secondary analysis, allowing researchers to explore new hypotheses without the time and cost associated with collecting new data.