Incremental training of machine learning tools

Technology related to incremental training of machine learning tools is disclosed. In one example of the disclosed technology, a method can include receiving operational parameters of a machine learning tool based on a primary set of training data. The machine learning tool can be a deep neural network. Input data can be applied to the machine learning tool to generate an output of the machine learning tool. A measure of prediction quality can be generated for the output of the machine learning tool. In response to determining the measure of prediction quality is below a threshold, incremental training of the operational parameters can be initiated using the input data as training data for the machine learning tool. Operational parameters of the machine learning tool can be updated based on the incremental training. The updated operational parameters can be stored.