Beyond Matching: Category-Guided Latent Intent Reasoning for Generative Retrieval in E-Commerce

2026-06-05

AI Summary

This work addresses the semantic gap between short user queries and product semantic identifiers (SIDs) in e-commerce search, along with stringent latency constraints. To this end, the authors propose CaLIR, a framework that performs coarse-to-fine implicit intent reasoning guided by category hierarchies, learning continuous latent states to align user shopping intent with SIDs without relying on explicit chain-of-thought reasoning that incurs high latency. CaLIR innovatively integrates query-aware intent path modeling, dynamic prefix Trie-constrained decoding, and hierarchical semantic reasoning, achieving substantial retrieval gains without compromising efficiency. Experiments demonstrate that CaLIR strikes a superior balance between retrieval effectiveness and inference efficiency across multilingual e-commerce datasets, while exhibiting strong transferability and robustness across diverse category taxonomies and generative backbone models.

Abstract

Generative retrieval offers a new paradigm for e-commerce search by mapping user queries directly to product Semantic Identifiers (SIDs). However, e-commerce queries are often short, noisy, attribute-heavy, and associated with multiple category-consistent products, creating a substantial representation gap between natural-language shopping intent and artificially constructed item SIDs. Explicit Chain-of-Thought (CoT) reasoning can help bridge this gap, but its extra generation cost is difficult to reconcile with the low-latency requirements of online e-commerce systems. To address this challenge, we propose CaLIR (Category-guided Latent Intent Reasoning), a category-guided latent intent reasoning framework for e-commerce generative retrieval. Rather than generating explicit textual rationales, CaLIR learns continuous latent intent states before SID decoding and uses product category hierarchies as a natural scaffold for coarse-to-fine intent reasoning. Specifically, we introduce hierarchical semantic reasoning to align latent states with category-level shopping intent, and query-wise reasoning enhancement to model diverse intent paths under multi-positive queries. CaLIR further combines a query-specific dynamic prefix trie, assembled from pre-indexed category-level tries, with reasoning-aware constrained decoding. Experiments on multilingual e-commerce search datasets show that CaLIR achieves a better balance between retrieval effectiveness and inference efficiency than existing methods, while also demonstrating transferability and robustness across induced hierarchies and different generative backbones.

Problem

• generative retrieval
• e-commerce search
• semantic identifier
• intent reasoning
• representation gap

Innovation

• Generative Retrieval
• Latent Intent Reasoning
• Category Hierarchy
• Constrained Decoding
• E-commerce Search