1. The document discusses primary and secondary data, methods of data collection, and data classification.
2. Primary data is original data collected directly by researchers, while secondary data was previously collected by others. Primary data collection methods include surveys, interviews, and experiments, while secondary data comes from existing sources like publications and records.
3. Data classification organizes data into categories to aid usage and protection, with the goals of making data easily retrievable, meeting compliance requirements, and increasing awareness of data sensitivity.