When it comes to statistical analysis, there are many possible sources of data depending on the research question, domain, and budget. Surveys and questionnaires can be useful for collecting primary data from a sample of the target population, however they must be carefully designed, sampled, and administered to prevent bias and errors. Experiments and tests are controlled methods for generating data by manipulating variables and measuring outcomes, though they can be costly, time-consuming, and ethically challenging. Administrative and operational records are data collected by organizations or agencies for their own purposes, such as sales or health records. They can provide large datasets but may also have quality issues, privacy concerns, or limited access. Lastly, online and social media data generated by users or platforms on the internet can offer insights into behaviors, opinions, and trends; however they can also be noisy, incomplete, or unrepresentative.