Individuals looking for the best method frequently ask, "How to Start a Secondary Data Analysis?" Historically, data analysts could only obtain data by collecting it themselves. This type of data, known as primary data, is still an important resource for data analysts. However, the technological advances in the last few decades have made many historical data readily available online for data analysts and researchers to access and use. As illustrated in this How to Start a Secondary Data Analysis diagram, this type of data, known as secondary data, is fueling a revolution in data analytics and data science. Many similarities exist between primary and secondary data.