I already have 2 datasets. One to use for training and one for testing. Both datasets are unbalanced (with similar percentages), with around 90% of label 1 . Will it be useful to balance the data if the test set is very unbalanced anyway? Instances of label 0 (which are 10%) are still enough.
If necessary, I would eventually use oversampling. Mine is a tripAdvisor review dataset, what would be the best technique to use in this case?
Are there any mixed techniques that use both undersampling and oversampling? or does it make little sense?