Towards a unified model for symbolic knowledge extraction with hypercube-based methods

Abstract

The XAI community is currently studying and developing symbolic knowledge-extraction (SKE) algorithms as a means to produce human-intelligible explanations for black-box machine learning predictors, so as to achieve believability in human-machine interaction. However, many extraction procedures exist in the literature, and choosing the most adequate one is increasingly cumbersome, as novel methods keep on emerging. Challenges arise from the fact that SKE algorithms are commonly defined based on theoretical assumptions that typically hinder practical applicability. This paper focuses on hypercube-based SKE methods, a quite general class of extraction techniques mostly devoted to regression-specific tasks. We first show that hypercube-based methods are flexible enough to support classification problems as well, then we propose a general model for them, and discuss how they support SKE on datasets, predictors, or learning tasks of any sort. Empirical examples are reported as well –based upon the PSyKE framework –, showing the applicability of hypercube-based methods to actual classification tasks.

Special issue for the 23rd workshop “from objects to agents” (WOA 2022)

“…The fifth paper of this special issue extends [6] and focuses upon a quite general class of SKE techniques, namely hypercube-based methods. Despite being commonly considered as regression-specific, the authors discuss why hypercube-based SKE methods are flexible enough to deal with classification problems as well.…”