Abstract: Recently there are major changes and evolution has been done on classification of data. Class imbalance problem become greatest issue in data mining. Imbalance problem occur where one of the two classes having more sample than other classes. The most of algorithm are more focusing on classification of major sample while ignoring or misclassifying minority sample. The minority samples are those that rarely occur but very important.. Class imbalance is one of the most challenges of machine learning and data mining fields. In this paper we focused on more techniques involve solving rare class or imbalanced problem.

Keywords: Class imbalance problem, data pre-processing, machine learning, and algorithm.