When I do a scatterplot showing the relationship between rater-a and rater-b, I would like to have a reference line that its slope is one (means both raters score the same).

 

     Has anyone encountered a similar problem or can help me?

 

     Thanks in advance...

Ching-Lin Hsieh, OT, Ph.D.
Lecturer, School of Occupational Therapy,
College of Medcine, National Taiwan University
WWW homepage: http://king.cc.ntu.edu.tw/~clhsieh/