203.3.8 Practice : Validating the Tree

Tree Validation

In previous section, we studied about Building a Decision Tree in R

• Accuracy=(TP+TN)/(TP+FP+FN+TN)
• Misclassification Rate=(FP+FN)/(TP+FP+FN+TN)

LAB: Tree Validation

• Find the accuracy of the classification for the Ecom_Cust_Survey model

predicted_values<-predict(Ecom_Tree,type="class")
actual_values<-Ecom_Cust_Survey$Overall_Satisfaction

conf_matrix<-table(predicted_values,actual_values)
conf_matrix

##                 actual_values
## predicted_values Dis Satisfied Satisfied
##    Dis Satisfied          6373       652
##    Satisfied                38      4749

accuracy<-(conf_matrix[1,1]+conf_matrix[2,2])/(sum(conf_matrix))
accuracy

## [1] 0.9415848