One Task Vector is not Enough: A Large-Scale Study for In-Context Learning

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Authors: Pavel Tikhonov, Ivan Valer'evich Oseledets, Elena Viktorovna Tutubalina
Cited by: 0

Abstract

In-context learning (ICL) enables Large Language Models (LLMs) to adapt to new tasks using few examples, with task vectors, defined as specific hidden state activations hypothesized to encode task information.Existing studies are limited by small-scale benchmarks, restricting comprehensive analysis.We introduce QUITEAFEW, a novel dataset of 3,096 diverse few-shot tasks, each with 30 input-output pairs derived from the Alpaca dataset.Experiments with Llama-3-8B and Qwen-3-8B on QUITEAFEW reveal: (1) task vector performance peaks at an intermediate layer, (2) effectiveness varies significantly by task type, and (3) complex tasks rely on multiple, subtaskspecific vectors rather than a single vector, suggesting distributed task knowledge representation.

Fields of Study & Subjects

Anomaly Detection Techniques and Applications

Publication details

Journal / source
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 4: Student Research Workshop)
Publisher
Association for Computational Linguistics
Pages
1451–1463
Publication date
1 January 2026
Language
EN