“…For example, in the medical domain, it is essential that machine learning models forward x-ray images that are difficult to classify (i.e., the model is uncertain about the prediction) to physicians for manual inspection. In the literature, several setups exist in which human experts augment and complement ML models: HITL systems are employed in supervised learning (e.g., Wang et al 2016, Kamar 2016, Wu, Xiao, Sun, Zhang, Ma & He 2021, semi-supervised learning (e.g., Wrede & Hellander 2019, Weber et al 2021, and reinforcement learning (e.g., Wu et al 2022, Liang et al 2017, Elmalaki 2021). However, these approaches generally require repetitive human effort that is growing with the number of unknown instances and the inaccuracy in detecting such instances.…”