I am working with unbalanced classes to solve a classification problem (whether individuals pay their fees or not). My class imbalance is 75% positive (paid) and 25% negative (unpaid). I have read that stratified kfolds is useful because it preserves the class balances while computing each fold and performing cross validation. However, I found stratified kfolds to perform worse than regular folds for my data. Can this happen or does something seem wrong? Unfortunately I cannot share the data and I realize the explanation might not be tailored to the specific data I have, but what are potential reasons for stratified kfolds performing worse?

  • $\begingroup$ K-fold solves the balance in each fold part, but does not solve your unbalanced data set part. You should take a look at how to deal with imbalance. $\endgroup$ – user2974951 Oct 15 '18 at 6:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.