A subjective rating or ranking questionnaire is generally easy for subjects to understand and can therefore be a simpler method for gathering data than other means.

Individual interviews are another well-functioning and often used method. The material obtained through open-ended questions and interviews is transcribed, and the data analysed using qualitative ...

It is easier than ever to use good statistical methods and data science practices to analyze the data. Without them, the data is just a pile of numbers. Look at artificial intelligence for guidance.