Rank Methods Spearman s

When the variables  under  consideration are  not capable  of quantitative  measurement but can  be arranged  in serial  order( ranks) we find  correlation  between  the ranks  of two series. This happens when we deal  with qualitative  characteristics such  as honesty beauty  etc. This method is called spearman rank difference methods or ranking methods and the  correlation coefficient  so obtained is  called ranks correlation coefficient  and is  denoted by r_s. This methods was developed by Charles Edward spearman a British psychologist in 1904.