University of Alaska Fairbanks
The authors analyze the interplay of density estimation and outlier detection in density-based outlier detection. By clear and principled decoupling of both steps, they formulate a generalization of density-based outlier detection methods based on kernel density estimation. Embedded in a broader framework for outlier detection, the resulting method can be easily adapted to detect novel types of outliers: while common outlier detection methods are designed for detecting objects in sparse areas of the data set, their method can be modified to also detect unusual local concentrations or trends in the data set if desired. It allows for the integration of domain knowledge and specific requirements. They demonstrate the flexible applicability and scalability of the method on large real world data sets.