Machine Learning Intermediate
decision boundary
The separator between classes learned by a model in a binary class or multi-class classification problems.
Plain English Explanation
The separator between classes learned by a model in a binary class or multi-class classification problems. For example, in the following image representing a binary classification problem, the decision boundary is the frontier between the orange class and the blue class:
How is it used?
Practitioners refer to decision boundary when building, training, or evaluating machine learning systems. It appears in research papers, product documentation, and technical discussions about AI capabilities and limitations.