I have a GitHub dataset of three variables (star_count, fork_count and watch_count) for each repository. Now, I want to find a popularity score using the three variables. For example, I can normalize the value of three variables and take average to calculate the popularity score for a repository.
Now, I will average the three variables if three variables are rank correlated. To calculate rank correlation between two variables, I can calculate Spearman’s rho. However, what is the way to calculate the rank correlation between three variables?
One approach I thought of calculating rank correlation of every pair of variables and check if the pairs are correlated. Will it be a good approach? Is there any statistical test to find rank correlation between three variables?