I am working on a multiclass classification which is to assign medical related queries of web search to certain departments of hospital.My classifier is based on the fastText.
I found for most conditions, the result is good enough say recall is 0.8 for Nephrology. However, for just one department, Dermatology, the recall is pretty low,like 0.5. Unfortunately, this label has most samples in the test data.
How can I improve the recall of one class while maintain the performance of other classes? Will ensembling method work?