An unclassified outlier is an outlier that does not resemble any recognized category of useful outlier. Novel outliers may otherwise be mislabeled as inliers or assigned to an existing category. section 15.3.2
Detect it by training one One-Class Support Vector Machine per known outlier category. Records inside a category’s learned boundary match that type; records outside every boundary remain unclassified. section 15.3.2
Category-specific OCSVM boundaries
For a dataset containing four known outlier types, train an OCSVM on examples of one type, such as a small cluster in the bottom right, then predict across the full dataset. Points matching none of the category boundaries are unclassified outliers. section 15.3.2
