MoTE: Mixture of Task Experts for Embedding Models

26 Sept 2024 (modified: 05 Feb 2025)Submitted to ICLR 2025EveryoneRevisionsBibTeXCC BY 4.0
Keywords: Embedding Models, Representation Learning, Mixture of Experts, Retrieval Augmented Generation, RAG, Search, Clustering, Classification
TL;DR: This paper builds on instruction embeddings literature introducing a new architecture with a dedicated set of parameters for each of the tasks and a task-aware training.
Abstract: Dense embeddings are essential for Retrieval-Augmented Generation (RAG), search, classification, and clustering systems. Recent methods improve dense embeddings by enriching them with instructions that incorporate downstream task information, enabling a single model to generate task-specific embedding spaces. However, we empirically show that requiring all tasks to share the same model parameters imposes significant representational limitations. To address these challenges, we introduce Mixture of Task Experts (MoTE), a novel transformer block designed for embedding architectures. MoTE employs dedicated parameter sets tailored to the unique requirements of each task and is paired with a task-aware training framework to improve representation quality. Experiments on 56 datasets spanning $7$ tasks demonstrate that MoTE outperforms instruction-conditioned models, achieving, on average, $1.62$ higher NDCG@10 on retrieval datasets, $1.54$ higher MAP on re-ranking datasets, and a $0.65$ improvement in overall performance. Notably, these gains are achieved without altering inference-time information, training data, inference speed, or number of active parameters.
Primary Area: unsupervised, self-supervised, semi-supervised, and supervised representation learning
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Submission Number: 6960
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