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Orion Weller

17 accepted papers

2026

On the Theoretical Limitations of Embedding-Based Retrieval

ICLR 2026poster

Vector embeddings have been tasked with an ever-increasing set of retrieval tasks over the years, with a nascent rise in using them for reasoning, instruction-following, coding, and more. These new benchmarks push embeddings to work for any query and any notion of relevance that could be given. Whil…

Cited by 0SourcecodeScholar
2026

Seq vs Seq: An Open Suite of Paired Encoders and Decoders

ICLR 2026poster

The large language model (LLM) community focuses almost exclusively on decoder-only language models, since they are easier to use for text generation. However, a large subset of the community still uses encoder-only models for tasks such as classification or retrieval. Previous work has attempted to…

Cited by 0SourcecodeScholar
2026

mmBERT: A Modern Multilingual Encoder with Annealed Language Learning

ICML 2026poster

Encoder-only language models are frequently used for a variety of language tasks, including classification and retrieval. However, there has been a lack of recent research efforts for encoder models, especially with respect to multilingual models. We introduce mmBERT, an encoder-only language model …

Cited by 0SourceScholar
2025

CLERC: A Dataset for U. S. Legal Case Retrieval and Retrieval-Augmented Analysis Generation

NAACL 2025findings

Legal professionals need to write analyses that rely on citations to relevant precedents, i.e., previous case decisions. Intelligence systems assisting legal professionals in writing such documents provide great benefits but are challenging to design. Such systems need to help locate, summarize, and…

2025

FollowIR: Evaluating and Teaching Information Retrieval Models to Follow Instructions

NAACL 2025long

Modern Language Models (LMs) are capable of following long and complex instructions that enable a large and diverse set of user requests. While Information Retrieval (IR) models use these LMs as the backbone of their architectures, virtually none of them allow users to provide detailed instructions…

2025

From Models to Microtheories: Distilling a Model's Topical Knowledge for Grounded Question-Answering

ICLR 2025poster

Recent reasoning methods (e.g., chain-of-thought) help users understand how language models (LMs) answer a single question, but they do little to reveal the LM’s overall understanding, or “theory,” about the question’s topic, making it still hard to trust the model. Our goal is to materialize such t…

2025

MMTEB: Massive Multilingual Text Embedding Benchmark

ICLR 2025poster

Text embeddings are typically evaluated on a narrow set of tasks, limited in terms of languages, domains, and task types. To circumvent this limitation and to provide a more comprehensive evaluation, we introduce the Massive Multilingual Text Embedding Benchmark (MMTEB) -- a large-scale community-dr…

2025

Promptriever: Instruction-Trained Retrievers Can Be Prompted Like Language Models

ICLR 2025poster

Instruction-tuned language models (LM) are able to respond to imperative commands, providing a more natural user interface compared to their base counterparts. In this work, we present Promptriever, the first retrieval model able to be prompted like an LM. To train Promptriever, we curate and releas…

2025

SELF-[IN]CORRECT: LLMs Struggle with Discriminating Self-Generated Responses

AAAI 2025technical

Can LLMs consistently improve their previous outputs for better results? For this to be true, LLMs would need to be better at discriminating among previously-generated alternatives, than generating initial responses. We explore the validity of this hypothesis in practice. We first formulate a unifie…

2025

Smarter, Better, Faster, Longer: A Modern Bidirectional Encoder for Fast, Memory Efficient, and Long Context Finetuning and Inference

ACL 2025long

Encoder-only transformer models such as BERT offer a great performance-size tradeoff for retrieval and classification tasks with respect to larger decoder-only models. Despite being the workhorse of numerous production pipelines, there have been limited Pareto improvements to BERT since its release.…

2024

Enhancing Systematic Decompositional Natural Language Inference Using Informal Logic

EMNLP 2024main

Recent language models enable new opportunities for structured reasoning with text, such as the construction of intuitive, proof-like textual entailment trees without relying on brittle formal logic. However, progress in this direction has been hampered by a long-standing lack of a clear protocol fo…

Cited by 9SourcePDFScholar
2024

Learning to Reason via Program Generation, Emulation, and Search

NeurIPS 2024poster

Program synthesis with language models (LMs) has unlocked a large set of reasoning abilities; code-tuned LMs have proven adept at generating programs that solve a wide variety of algorithmic symbolic manipulation tasks (e.g. word concatenation). However, not all reasoning tasks are easily expressibl…

2023

When Do Decompositions Help for Machine Reading?

EMNLP 2023short main

Answering complex questions often requires multi-step reasoning in order to obtain the final answer. Most research into decompositions of complex questions involves open-domain systems, which have shown success in using these decompositions for improved retrieval. In the machine reading setting, how…

Cited by 0SourceScholar
2022

End-to-End Speech Translation for Code Switched Speech

ACL 2022findings

Code switching (CS) refers to the phenomenon of interchangeably using words and phrases from different languages. CS can pose significant accuracy challenges to NLP, due to the often monolingual nature of the underlying systems. In this work, we focus on CS in the context of English/Spanish conversa…

2022

Pretrained Models for Multilingual Federated Learning

NAACL 2022long

Since the advent of Federated Learning (FL), research has applied these methods to natural language processing (NLP) tasks. Despite a plethora of papers in FL for NLP, no previous works have studied how multilingual text impacts FL algorithms. Furthermore, multilingual text provides an interesting a…

2022

When to Use Multi-Task Learning vs Intermediate Fine-Tuning for Pre-Trained Encoder Transfer Learning

ACL 2022short

Transfer learning (TL) in natural language processing (NLP) has seen a surge of interest in recent years, as pre-trained models have shown an impressive ability to transfer to novel tasks. Three main strategies have emerged for making use of multiple supervised datasets during fine-tuning: training…

2021

Exploring the Relationship Between Algorithm Performance, Vocabulary, and Run-Time in Text Classification

NAACL 2021long

Text classification is a significant branch of natural language processing, and has many applications including document classification and sentiment analysis. Unsurprisingly, those who do text classification are concerned with the run-time of their algorithms, many of which depend on the size of th…