Out-of-Distribution Aware Classification for Tabular Data

Out-of-distribution (OOD) aware classification aims to classify in-distribution samples into their respective classes while simultaneously detecting OOD samples. Previous works have largely focused on the image domain, where images from an unrelated dataset can serve as auxiliary OOD training data. In this work, we address OOD-aware classification for tabular data, where an unrelated dataset cannot be used as OOD training data. A potential solution to OOD-aware classification involves filtering out OOD samples using an outlier detection method and classifying the remaining samples with a traditional classification model. However, seamlessly integrating this approach into downstream optimization tasks is challenging due to the employment of multiple methods. Our approach is turning OOD-aware classification into traditional classification by augmenting the in-distribution training data with synthesized OOD data. This approach continues leveraging traditional classification methods while detecting OOD samples, and the learned model retains the same mathematical properties as traditional classification models, thus, it can be easily integrated into downstream tasks. We evaluate these benefits empirically using real-life datasets. Code is available at https://github.com/ah-ansari/OCT.