In this video, I use a real-world case to show you how to remove invalid data in R. I introduce four scenarios, including non-data rows, testing data, incomplete responses, and uncommon responses.
The lecture note can be found here: https://drive.google.com/file/d/1B1OIngJv-o9DqtS1-CYxcMsknsZo2H6C/view?usp=sharing
The sample data used in this video: https://drive.google.com/file/d/13ivnj2So_nKoBVOTByGR5wV7uBi7DhYE/view?usp=sharing
The video about data import in R: https://youtu.be/fMPLkObZUqQ
