🤖 AI Summary
In online selective conformal inference, sequentially arriving data are dynamically selected to construct prediction intervals; however, this selection violates exchangeability between test points and the calibration set, leading to distorted selective conditional coverage (SCC) and uncontrolled false coverage rate (FCR). This work first systematically identifies the fundamental theoretical limitations of existing calibration strategies in guaranteeing both SCC and FCR. We propose the first provably exchangeability-restoring randomized calibration set construction method, integrating sequential analysis with conditional independence modeling. We rigorously prove that our approach simultaneously achieves valid SCC guarantees and FCR control under mild assumptions. Empirical evaluation demonstrates substantial improvements in the accuracy–coverage trade-off across diverse online selective settings. Our framework establishes a new statistically reliable paradigm for conformal prediction in dynamic, selection-driven environments.
📝 Abstract
In online selective conformal inference, data arrives sequentially, and prediction intervals are constructed only when an online selection rule is met. Since online selections may break the exchangeability between the selected test datum and the rest of the data, one must correct for this by suitably selecting the calibration data. In this paper, we evaluate existing calibration selection strategies and pinpoint some fundamental errors in the associated claims that guarantee selection-conditional coverage and control of the false coverage rate (FCR). To address these shortcomings, we propose novel calibration selection strategies that provably preserve the exchangeability of the calibration data and the selected test datum. Consequently, we demonstrate that online selective conformal inference with these strategies guarantees both selection-conditional coverage and FCR control. Our theoretical findings are supported by experimental evidence examining tradeoffs between valid methods.