In this tutorial, we go through a practical example of Stata's "merge" and "append" commands with the goal of combining three different data sets into one combined data set ready for statistical analysis. Remember, the official Stata help files (type "help [command]" in the Stata command line) and the Stata forum (statalist.org) offer valuable support. Additionally, search engines (e.g., Google and Bing) and artificial intelligence tools (e.g., ChatGPT and Gemini) can assist you in finding the code you need. You can download the datasets, additional explanations, and the Stata "Do Files" for the tutorial by following this link: https://drive.google.com/drive/folders/1dD_XvNMlJ9J-HfNzzRo5ZeaJ9_Zqo654?usp=sharing Access the "Common Mistakes and How to Fix Them" PDF directly here: https://drive.google.com/file/d/1-G0Q6E0RuuS7PQNGKMrMBYNkknhpdZSm/view?usp=drive_link