We develop conformal prediction methods for constructing valid predictive confidence sets in multiclass and multilabel problems without assumptions on the data generating distribution. A challenge here is that typical conformal prediction methods---which give marginal validity (coverage) guarantees---provide uneven coverage, in that they address easy examples at the expense of essentially ignoring difficult examples. By leveraging ideas from quantile regression, we build methods that always guarantee correct coverage but additionally provide (asymptotically optimal) conditional coverage for both multiclass and multilabel prediction problems. To address the potential challenge of exponentially large confidence sets in multilabel prediction, we build tree-structured classifiers that efficiently account for interactions between labels. Our methods can be bolted on top of any classification model---neural network, random forest, boosted tree---to guarantee its validity. We also provide an empirical evaluation suggesting the more robust coverage of our confidence sets.

本文介绍一种基于分位数回归和树状结构分类器的符合性预测方法，可以有效解决多分类和多标签问题中难易样本分布不均匀、信心区间过大等挑战，且可以和任何分类模型结合使用并保证有效性。

多类别和多标签预测中的有效和验证置信集