  Few-shot recognition learns a recognition model with very few (e.g., 1 or 5)
images per category, and current few-shot learning methods focus on improving
the average accuracy over many episodes. We argue that in real-world
applications we may often only try one episode instead of many, and hence
maximizing the worst-case accuracy is more important than maximizing the
average accuracy. We empirically show that a high average accuracy not
necessarily means a high worst-case accuracy. Since this objective is not
accessible, we propose to reduce the standard deviation and increase the
average accuracy simultaneously. In turn, we devise two strategies from the
bias-variance tradeoff perspective to implicitly reach this goal: a simple yet
effective stability regularization (SR) loss together with model ensemble to
reduce variance during fine-tuning, and an adaptability calibration mechanism
to reduce the bias. Extensive experiments on benchmark datasets demonstrate the
effectiveness of the proposed strategies, which outperforms current
state-of-the-art methods with a significant margin in terms of not only
average, but also worst-case accuracy. Our code is available at
https://github.com/heekhero/ACSR.
