# Confusion Matrix: nominal vs interval

I want to evaluate my model with help of a confusion matrix. Which measure can I use to consider that my data is interval scaled (eg.:1,2,3,4,5,6,7,8,9,10) ? As I understand the Kappa measure is often used for nominal scaled data (eg.: red, green blue). If I use the Kappa estimate for the interval scaled data a misclassification of 1 --> 2 (1) is considered to be as severe as a misclassification of 1 --> 8 (2). However, the misclassification (1) is much less sever than the misclassification (2). How can I account for this in a confusion matrix?

• you can use weighted kappa, if you use r, try reading the help from kappa2. – ceoec May 13 '15 at 8:07
• In kappa 2 I should use the '"squared" weight for a interval scale for the above mentioned example, right? – kalakaru May 13 '15 at 11:18
• yes i believe so... – ceoec May 13 '15 at 13:07
• are you also familiar with the cohen.test from the psych package? If yes, can you maybe answer this question: stats.stackexchange.com/questions/152799/… – kalakaru May 18 '15 at 9:27