activity
20242026
most citedIs Cosine-Similarity of Embeddings Really About Similarity?

133 citations · 133 across the 8 of their papers we have counts for

collaborators

8 papers

cs.IR2026

Mult-DPO: Multinomial Direct Preference Optimization for Recommender Systems

Yaochen Zhu, Harald Steck, James McInerney +4

Direct preference optimization (DPO) is a simple and effective alignment strategy for large language models (LLMs) based on pairwise preferences. In recommender systems, however, u…

cs.CL2026

Beyond Continuity: Challenges of Context Switching in Multi-Turn Dialogue with LLMs

Aditya Sinha, Harald Steck, Vito Ostuni +1

Users interacting with Large Language Models (LLMs) in a multi-turn conversation routinely refine their requests or pivot to new topics. LLMs, however, often miss these topic shift…

cs.IR2025

Does Weighting Improve Matrix Factorization for Recommender Systems?

Alex Ayoub, Samuel Robertson, Dawen Liang +2

Matrix factorization is a widely used approach for top-N recommendation and collaborative filtering. When implemented on implicit feedback data (such as clicks), a common heuristic…

cs.IR2025

Rank-GRPO: Training LLM-based Conversational Recommender Systems with Reinforcement Learning

Yaochen Zhu, Harald Steck, Dawen Liang +4

Large language models (LLMs) are reshaping the recommender system paradigm by enabling users to express preferences and receive recommendations through conversations. Yet, aligning…

cond-mat.str-el2025

Interacting Chern insulator transition on the sphere: revealing the Gross-Neveu-Yukawa criticality

Zhi-Qiang Gao, Taige Wang, Dung-Hai Lee

In two spatial dimensions, the transition between topological and trivial Chern insulators exemplifies a class of beyond-Landau critical phenomena. We show that the interaction-dri…

cs.IR2025

Collaborative Retrieval for Large Language Model-based Conversational Recommender Systems

Yaochen Zhu, Chao Wan, Harald Steck +4

Conversational recommender systems (CRS) aim to provide personalized recommendations via interactive dialogues with users. While large language models (LLMs) enhance CRS with their…

cs.IR2024

Reindex-Then-Adapt: Improving Large Language Models for Conversational Recommendation

Zhankui He, Zhouhang Xie, Harald Steck +4

Large language models (LLMs) are revolutionizing conversational recommender systems by adeptly indexing item content, understanding complex conversational contexts, and generating…

cs.IR2024★ 133 cited

Is Cosine-Similarity of Embeddings Really About Similarity?

Harald Steck, Chaitanya Ekanadham, Nathan Kallus

Cosine-similarity is the cosine of the angle between two vectors, or equivalently the dot product between their normalizations. A popular application is to quantify semantic simila…