Improving LLMs for Recommendation with Out-Of-Vocabulary Tokens

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Huang, Ting-Ji, Yang, Jia-Qi, Shen, Chunxu, Liu, Kai-Qi, Zhan, De-Chuan, Ye, Han-Jia
Natura: Preprint
Pubblicazione: 2024
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866929383586922496
author Huang, Ting-Ji
Yang, Jia-Qi
Shen, Chunxu
Liu, Kai-Qi
Zhan, De-Chuan
Ye, Han-Jia
author_facet Huang, Ting-Ji
Yang, Jia-Qi
Shen, Chunxu
Liu, Kai-Qi
Zhan, De-Chuan
Ye, Han-Jia
contents Characterizing users and items through vector representations is crucial for various tasks in recommender systems. Recent approaches attempt to apply Large Language Models (LLMs) in recommendation through a question and answer format, where real users and items (e.g., Item No.2024) are represented with in-vocabulary tokens (e.g., "item", "20", "24"). However, since LLMs are typically pretrained on natural language tasks, these in-vocabulary tokens lack the expressive power for distinctive users and items, thereby weakening the recommendation ability even after fine-tuning on recommendation tasks. In this paper, we explore how to effectively tokenize users and items in LLM-based recommender systems. We emphasize the role of out-of-vocabulary (OOV) tokens in addition to the in-vocabulary ones and claim the memorization of OOV tokens that capture correlations of users/items as well as diversity of OOV tokens. By clustering the learned representations from historical user-item interactions, we make the representations of user/item combinations share the same OOV tokens if they have similar properties. Furthermore, integrating these OOV tokens into the LLM's vocabulary allows for better distinction between users and items and enhanced capture of user-item relationships during fine-tuning on downstream tasks. Our proposed framework outperforms existing state-of-the-art methods across various downstream recommendation tasks.
format Preprint
id arxiv_https___arxiv_org_abs_2406_08477
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Improving LLMs for Recommendation with Out-Of-Vocabulary Tokens
Huang, Ting-Ji
Yang, Jia-Qi
Shen, Chunxu
Liu, Kai-Qi
Zhan, De-Chuan
Ye, Han-Jia
Information Retrieval
Characterizing users and items through vector representations is crucial for various tasks in recommender systems. Recent approaches attempt to apply Large Language Models (LLMs) in recommendation through a question and answer format, where real users and items (e.g., Item No.2024) are represented with in-vocabulary tokens (e.g., "item", "20", "24"). However, since LLMs are typically pretrained on natural language tasks, these in-vocabulary tokens lack the expressive power for distinctive users and items, thereby weakening the recommendation ability even after fine-tuning on recommendation tasks. In this paper, we explore how to effectively tokenize users and items in LLM-based recommender systems. We emphasize the role of out-of-vocabulary (OOV) tokens in addition to the in-vocabulary ones and claim the memorization of OOV tokens that capture correlations of users/items as well as diversity of OOV tokens. By clustering the learned representations from historical user-item interactions, we make the representations of user/item combinations share the same OOV tokens if they have similar properties. Furthermore, integrating these OOV tokens into the LLM's vocabulary allows for better distinction between users and items and enhanced capture of user-item relationships during fine-tuning on downstream tasks. Our proposed framework outperforms existing state-of-the-art methods across various downstream recommendation tasks.
title Improving LLMs for Recommendation with Out-Of-Vocabulary Tokens
topic Information Retrieval
url https://arxiv.org/abs/2406.08477