Degree of  Correlation ship

1.Perfect Correlation: When  changes  in  two related variables are  exactly  proportional  there is  perfect correlation between  them. In case  the equal  proportional  changes are in the same direction there is perfect positive correlation between  the two  variables. On  the other  hand  if equal  proportional  changes  are in the reverse  direction there is perfect  negative  correlation.

2.Absence  of Correlation : In case  no interdependence exists between  the two variables  or no relationship  is found  between the changes in them  there is  absence of correlation.

3.Limited Degree of Correlation: If there are unequal  changes  in the  two variable  in the same  direction correlation is said  to be limited  positive and if there  are unequal  changes in the opposite  direction the correlation  is limited  negative. The  limited  degree of correlation can be  high moderate  low.