Most of the recent works on post-hoc example-based eXplainable AI (XAI) methods revolves around employing counterfactual explanations to provide justification of the predictions made by AI systems. Counterfactuals show what changes to the input-features change the output decision. However, a lesser-known, special-case of the counterfacual is the semi-factual, which provide explanations about what changes to the input-features do not change the output decision. Semi-factuals are potentially as useful as counterfactuals but have received little attention in the XAI literature. My doctoral research aims to establish a comprehensive framework for the use of semi-factuals in XAI by developing novel methods for their computation, supported by user tests.

Recently, counterfactuals using “if-only” explanations have become very popular in eXplainable AI (XAI), as they describe which changes to feature-inputs of a black-box AI system result in changes to a (usually negative) decision-outcome. Even more recently, semi-factuals using “even-if” explanations have gained more attention. They elucidate the feature-input changes that do not change the decision-outcome of the AI system, with a potential to suggest more beneficial recourses. Some semi-factual methods use counterfactuals to the query-instance to guide semi-factual production (so-called counterfactual-guided methods ), whereas others do not (so-called counterfactual-free methods ). In this work, we perform comprehensive tests of 8 semi-factual methods on 7 datasets using 5 key metrics, to determine whether counterfactual guidance is necessary to find the best semi-factuals. The results of these tests suggests not, but rather that computing other aspects of the decision space lead to better semi-factual XAI.

Very recently, semi-factual explanations have emerged in Explainable AI (XAI) as a new and potentially important explanation strategy. Semi-factuals employ “Even if...” reasoning, as opposed to the “If only...” reasoning of counterfactuals. Counterfactuals inform users about what feature-differences lead to changes in an outcome (e.g., “ if only you asked for a lower loan, you would have been successful.”), whereas semi-factuals inform them about what feature-differences lead to the outcome remaining the same (e.g., “ Even if you asked for a lower loan, you would still have been unsuccessful”). Semi-factuals have the potential to be as important as their popular counterfactual siblings. However, the AI/ML and XAI communities have by and large struggled to imagine useful application-scenarios for semi-factuals. In this paper, we summarize recent work on semi-factual explanation and trace a roadmap for application-focused research in the area. We begin by outlining the main constraints identified for semi-factual optimization proposed in the literature, before summarizing the applications of semi-factuals proposed to-date. Then, we sketch several directions for future applications and research using semi-factuals. Finally, though semi-factuals are highly promising (especially with regard to algorithmic recourse), they have a potential for ethical misuse that we discuss in our conclusions.

Recently, eXplainable AI (XAI) research has focused on counterfactual explanations as post-hoc justifications for AI-system decisions (e.g., a customer refused a loan might be told “if you asked for a loan with a shorter term, it would have been approved”). Counterfactuals explain what changes to the input-features of an AI system change the output-decision. However, there is a sub-type of counterfactual, semi-factuals, that have received less attention in AI (though the Cognitive Sciences have studied them more). This paper surveys semi-factual explanation, summarising historical and recent work. It defines key desiderata for semi-factual XAI, reporting benchmark tests of historical algorithms (as well as a novel, naïve method) to provide a solid basis for future developments.

Massive Open Online Courses (MOOCs) are the new revolution in the field of e-learning, providing a large number of courses in different domains to a wide range of learners. Due to the availability of several MOOC providers (including edX, Coursera, Udacity, FutureLearn), a specific domain has multiple courses spread across these platforms that confuses a learner on selecting the most suitable course for him. It is a tedious manual task for the learner to browse through various courses before he finds the best course that meets his learning requirements and objectives. MoocRec is a unique learning styles-oriented system that recommends the most suitable courses to a learner from different MOOC platforms based on their learning styles and individual needs. The courses are recommended based on the mapping of Felder and Silverman learning styles with the standard video styles used in MOOC videos (including talking head, slide, tutorial/demonstration). MoocRec also allows the learners to search for courses using specific topics to provide an enhanced personalized learning environment. Results show that MoocRec is strongly reliable and can be used for personalized learning.