Ranking something means deciding which one is better or worse than another. The superiority and inferiority ranking method is a way for people to say which one of two things is better, or more important than the other. For example, if you wanted to know which of two books is the better one, you could use the superiority and inferiority ranking method. You would look at different things, like the author, the subject matter, the quality of the writing, and other factors, and then you would decide which book is better than the other.