Minority class (machine learning)
The less common label in aclass-imbalanced dataset. For example, given a dataset containing 99% negative labels and 1% positive labels, the positive labels are the minority class.1
Notes
A training set with a million examples sounds impressive. However, if the minority class is poorly represented, then even a very large training set might be insufficient. Focus less on the total number of examples in the dataset and more on the number of examples in the minority class.1
If your dataset doesn’t contain enough minority class examples, consider using downsampling to supplement the minority class.1