Knowledge transfer for causal discovery

Subject-specific causal discovery methods could help to make better decisions in domains where there are variations on causal relations across subjects, such as neuroscience and genetics. However, discovering subject-specific causal models from limited data sets could be challenging. Although there are several causal discovery methods, most of them are focused on finding the common causal relations of a population from data sets with enough samples. The issue of discovering subject-specific causal relations from limited data sets has not been sufficiently explored. In this paper, we propose a knowledge transfer method for discovering subject-specific causal models. Our method discovers causal probabilistic graphical models, up to Markov equivalence classes, from discrete and continuous data sets. We hypothesized that transferring weighted instances of additional sources according to their discrepancy with target instances helps to compensate for the lack of target data and improves the performance of a scored-based causal discovery method. Experimental results on synthetic data sets and benchmark causal Bayesian networks show that our proposal, under few target samples, outperforms significantly in adjacency and arrowhead recovery the baseline and alternative methods (C) 2021 Elsevier Inc. All rights reserved.