Recommender systems have become integral to many online services, leveraging user data to provide personalized recommendations. However, as these systems grow in complexity, understanding the rationale behind their recommendations becomes increasingly difficult. Explainable Artificial Intelligence (XAI) has emerged as a crucial field addressing this challenge, particularly in ensuring transparency and trustworthiness in automated decision-making processes. In this article, we introduce Learning to eXplain Recommendations (LXR) , a scalable, model-agnostic framework designed to generate counterfactually correct explanations for recommender systems. LXR generates explanations for recommendations produced by any differentiable recommender system. By leveraging both factual and counterfactual loss terms, LXR offers robust, accurate, and computationally efficient explanations that reflect the model’s internal decision-making process. A key feature of LXR is its focus on the factual correctness of explanations through counterfactual reasoning, bridging the gap between plausible and accurate explanations. Unlike traditional approaches that rely on exhaustive perturbations of user data, LXR uses a self-supervised learning method to generate explanations efficiently, without sacrificing accuracy. LXR operates in two stages: a pre-training step and a novel Inference-Time Fine-tuning (ITF) step that refines explanations at the individual recommendation level, significantly improving accuracy with minimal computational overhead. Additionally, LXR is applied to hybrid recommender models incorporating demographic data, demonstrating its versatility across real-world scenarios. Finally, we also showcase LXR’s ability to explain recommendations at various ranks within a user’s recommendation list. As a secondary contribution, we introduce several novel evaluation metrics, inspired by saliency maps from computer vision, to rigorously assess the counterfactual correctness of explanations in recommender systems. Our results demonstrate that LXR sets a new benchmark for explainability, providing accurate, transparent, and interpretable explanations. The code is available on our GitHub repository: https://github.com/DeltaLabTLV/LXR_ .

Counterfactual evaluation provides a promising framework for assessing explanation fidelity in recommender systems, but perturbation metrics adapted from computer vision suffer three key limitations: (1) they conflate explaining and contradictory features, (2) they average over entire user histories instead of prioritizing concise, high-impact explanations, and (3) they use fixed-percentage perturbations, leading to inconsistencies across users.We introduce refined counterfactual metrics that focus on the most relevant explaining features, exclude contradictory elements, and assess fidelity at a fixed explanation length, ensuring a more consistent and interpretable evaluation.Our code is at: https:// github.com/DeltaLabTLV/FidelityMetrics4XRec

Knowledge Graph (KG)-based recommender systems utilize both Collaborative Filtering (CF) data and informative KG data to improve prediction accuracy. Path-based KG methods are a family of KG-based recommendation models that explore the interlinks within a knowledge graph in order to enhance the connectivity between users and items with rich complementary information. A key advantage of path-based KG methods stems from their ability to enable intuitive explanations naturally. In this work, we present a novel path-based algorithm that employs neural attention in order to better extract the relevant information from the unified graph. Evaluations based on public KG recommendation datasets indicate a clear advantage to the proposed method compared to state-of-the-art path-based alternatives. Furthermore, we show that this advantage also extends to cold items where a better utilization of the KG leads to improved predictions in cases where no CF data is available. Finally, by performing attention-score analysis, we demonstrate the ability of our approach to provide better interpretability into the model’s inner workings as well as extract more intuitive explanations. The code for this work is publicly available on GitHub: https://github.com/DeltaLabTLV/KPAR .

In the field of recommender systems, explainability remains a pivotal yet challenging aspect. To address this, we introduce the Learning to eXplain Recommendations (LXR) framework, a post-hoc, model-agnostic approach designed for providing counterfactual explanations. LXR is compatible with any differentiable recommender algorithm and scores the relevance of user data in relation to recommended items. A distinctive feature of LXR is its use of novel self-supervised counterfactual loss terms, which effectively highlight the most influential user data responsible for a specific recommended item. Additionally, we propose several innovative counterfactual evaluation metrics specifically tailored for assessing the quality of explanations in recommender systems. Our code is available on our GitHub repository: https://github.com/DeltaLabTLV/LXR.

The workshop focus is on considering temporal aspects for recommender systems in general, regardless of the specific domain and application, trying to develop a holistic approach for dealing with temporal aspects in recommender systems, like personal assistants, news, tourism, health care, TV, e-commerce, social networks and so on.