I am working on a multi class text classification dataset which has 2719 data (only training set is available test set is not available) and 256 classes. Sentence length of each data is very short, average sentence length is 5 and many data has only single word. Issue I am facing is out of 256 classes 81 classes have only single data. I have tried Naive bayes with TF-IDF but the accuracy is very poor. Could some one suggest good approach to proceed ?
Thanks in advance