In-Context Learning of Soft Nearest Neighbor Classifiers for Intelligible Tabular Machine Learning

With in-context learning foundation models like TabPFN excelling on small supervised tabular learning tasks, it has been argued that "boosted trees are not the best default choice when working with data in tables". 1 However, such foundation models are inherently blackbox models that do not provide interpretable predictions.We introduce a novel learning task to train ICL models to act as a nearest neighbor algorithm, which enables intelligible inference and does not decrease performance empirically.