I have a dataset with class imbalance about (1:10). I applied a SMOTE method by slitting the dataset into training and dev.
I over sampled the training set using a SMOTE method and divided this set into training and test to build a RF classifier.
When I evaluate the RF classifier on the dev set which has not be over sampled it preforms quite poorly.
Is it standard that I would apply SMOTE to the dev set as well?