Greater values of kappa indicate stronger agreement among ratings.
If kappa = 1, agreement is perfect.
If kappa = 0, agreement is the same as would be expected by chance.
If kappa < 0, agreement is weaker than expected by chance. This rarely happens.
A widely used guideline suggest: “Values of kappa greater than 0.75 indicates good to excellent agreement (with a maximum kappa = 1); value in between 0.75 and 0.7 indicate that it should be accepted, values less than 0.7 shows that it needs improvement, values less than 0.40 indicate poor agreement”.