This document provides an overview of secondary data collection methods. It defines secondary data as data that has already been collected and analyzed by others. The purposes of secondary data include extracting relevant information from other sources, fact finding, and model building. Some key advantages of secondary data are that it saves costs, time, and effort since the data already exists. Sources of secondary data can be internal sources from within an organization or external sources from outside organizations like the government, newspapers, books, and commercial data firms. The document discusses factors to consider with secondary data like availability, relevance, reliability, adequacy, and accuracy. It provides an example of how to map secondary data sources in a literature review.