PhD Seminar • Artificial Intelligence & Machine Learning • FLARE: Fusing Language Models and Collaborative Architectures for Recommender Enhancement

Wednesday, October 22, 2025 12:00 pm - 1:00 pm EDT (GMT -04:00)

Please note: This PhD seminar will take place in DC 3301.

Liam Hebert, PhD candidate
David R. Cheriton School of Computer Science

SupervisorsProfessors Robin Cohen & Lukasz Golab

A prominent trend in recommender systems involves replacing ID-based collaborative filtering models with architectures that rely solely on textual item descriptions. This work begins by challenging the premise of this trend, demonstrating that a thoroughly tuned ID-only baseline (Bert4Rec) is significantly more competitive than previously reported. This finding establishes the continued importance of collaborative signals and motivates our proposal of a hybrid solution. 

We introduce FLARE (Fusing Language models and collaborative Architectures for Recommender Enhancement), a novel hybrid recommender that integrates a collaborative filtering model with a language model using a Perceiver network. To ensure the practical relevance of our findings, we evaluate FLARE on both standard and large-scale, high-vocabulary datasets, establishing new benchmarks for the latter. Furthermore, we propose and evaluate critiquing as a novel task to assess a model's ability to incorporate explicit user intent, a critical form of contextual understanding. Our results show that FLARE achieves strong performance and effectively integrates user intent, validating the superiority of a hybrid approach that unifies both collaborative and semantic signals.