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Alexander Koller

28 accepted papers

2026

On the Ability of Transformers to Verify Plans

ICML 2026poster

Transformers have shown inconsistent success in AI planning tasks, and theoretical understanding of when generalization should be expected has been limited. We take important steps towards addressing this gap by analyzing the ability of decoder-only models to verify whether a given plan correctly so…

Cited by 0SourceScholar
2025

A Knapsack by Any Other Name: Presentation impacts LLM performance on NP-hard problems

EMNLP 2025

To investigate the effect of problem presentation on LLMs’ ability to solve optimization problems, we introduce the dataset of Everyday Hard Optimization Problems (EHOP), a collection of NP-hard problems expressed in natural language. EHOP includes problem formulations that could be found in compute

Cited by 0SourcePDFScholar
2025

Evaluating Spatiotemporal Consistency in Automatically Generated Sewing Instructions

EMNLP 2025

In this paper, we propose a novel, automatic tree-based evaluation metric for LLM-generated step-by-step assembly instructions, that more accurately reflects spatiotemporal aspects of construction than traditional metrics such as BLEU and BERT similarity scores. We apply our proposed metric to the d

Cited by 0SourcePDFScholar
2025

LLMs instead of Human Judges? A Large Scale Empirical Study across 20 NLP Evaluation Tasks

ACL 2025short

There is an increasing trend towards evaluating NLP models with LLMs instead of human judgments, raising questions about the validity of these evaluations, as well as their reproducibility in the case of proprietary models. We provide JUDGE-BENCH, an extensible collection of 20 NLP datasets with hum…

2025

LLMs syntactically adapt their language use to their conversational partner

ACL 2025short

It has been frequently observed that human speakers align their language use with each other during conversations. In this paper, we study empirically whether large language models (LLMs) exhibit the same behavior of conversational adaptation.We construct a corpus of conversations between LLMs and f…

Cited by 0SourcePDFScholar
2025

Language models can learn implicit multi-hop reasoning, but only if they have lots of training data

EMNLP 2025

Implicit reasoning is the ability of a language model to solve multi-hop reasoning tasks in a single forward pass, without chain of thought.We investigate this capability using GPT2-style language models trained from scratch on controlled k -hop reasoning datasets ( k = 2, 3, 4 ). We show that while

2025

Playpen: An Environment for Exploring Learning From Dialogue Game Feedback

EMNLP 2025

Interaction between learner and feedback-giver has come into focus recently for post-training of Large Language Models (LLMs), through the use of reward models that judge the appropriateness of a model’s response. In this paper, we investigate whether Dialogue Games—goal-directed and rule-governed a

2025

Triangulating LLM Progress through Benchmarks, Games, and Cognitive Tests

EMNLP 2025

We examine three evaluation paradigms: standard benchmarks (e.g., MMLU and BBH), interactive games (e.g., Signalling Games or Taboo), and cognitive tests (e.g., for working memory or theory of mind). First, we investigate which of the former two—benchmarks or games—is most effective at discriminatin

2024

A Corpus of German Abstract Meaning Representation (DeAMR)

COLING 2024main

We present the first comprehensive set of guidelines for German Abstract Meaning Representation (Deutsche AMR, DeAMR) along with an annotated corpus of 400 DeAMR. Taking English AMR (EnAMR) as our starting point, we propose significant adaptations to faithfully represent the structure and semantics…

2024

ADaPT: As-Needed Decomposition and Planning with Language Models

NAACL 2024findings

Large Language Models (LLMs) are increasingly being used for interactive decision-making tasks requiring planning and adapting to the environment. Recent works employ LLMs-as-agents in broadly two ways: iteratively determining the next action (iterative executors) or generating plans and executing s…

Cited by 92SourcePDFScholar
2024

Closing the Curious Case of Neural Text Degeneration

ICLR 2024poster

Despite their ubiquity in language generation, it remains unknown why truncation sampling heuristics like nucleus sampling are so effective. We provide a theoretical explanation for the effectiveness of the truncation sampling by proving that truncation methods that discard tokens below some probabi…

2024

SIP: Injecting a Structural Inductive Bias into a Seq2Seq Model by Simulation

ACL 2024long

Strong inductive biases enable learning from little data and help generalization outside the training distribution. Popular neural architectures such as Transformers lack strong structural inductive biases for seq2seq NLP tasks on their own. Consequently, they struggle with systematic generalization…

2024

Scope-enhanced Compositional Semantic Parsing for DRT

EMNLP 2024main

Discourse Representation Theory (DRT) distinguishes itself from other semantic representation frameworks by its ability to model complex semantic and discourse phenomena through structural nesting and variable binding. While seq2seq models hold the state of the art on DRT parsing, their accuracy deg…

2024

Strengthening Structural Inductive Biases by Pre-training to Perform Syntactic Transformations

EMNLP 2024main

Models need appropriate inductive biases to effectively learn from small amounts of data and generalize systematically outside of the training distribution. While Transformers are highly versatile and powerful, they can still benefit from enhanced structural inductive biases for seq2seq tasks, espec…

2023

Compositional Generalization without Trees using Multiset Tagging and Latent Permutations

ACL 2023long

Seq2seq models have been shown to struggle with compositional generalization in semantic parsing, i.e. generalizing to unseen compositions of phenomena that the model handles correctly in isolation. We phrase semantic parsing as a two-step process: we first tag each input token with a multiset of ou…

2023

SLOG: A Structural Generalization Benchmark for Semantic Parsing

EMNLP 2023long main

The goal of compositional generalization benchmarks is to evaluate how well models generalize to new complex linguistic expressions. Existing benchmarks often focus on lexical generalization, the interpretation of novel lexical items in syntactic structures familiar from training; structural general…

Cited by 0SourcecodeScholar
2023

We're Afraid Language Models Aren't Modeling Ambiguity

EMNLP 2023long main

Ambiguity is an intrinsic feature of natural language. Managing ambiguity is a key part of human language understanding, allowing us to anticipate misunderstanding as communicators and revise our interpretations as listeners. As language models are increasingly employed as dialogue interfaces and wr…

Cited by 0SourcecodeScholar
2023

What’s the Meaning of Superhuman Performance in Today’s NLU?

ACL 2023long

In the last five years, there has been a significant focus in Natural Language Processing (NLP) on developing larger Pretrained Language Models (PLMs) and introducing benchmarks such as SuperGLUE and SQuAD to measure their abilities in language understanding, reasoning, and reading comprehension. Th…

Cited by 24SourcePDFScholar
2021

Aligning Actions Across Recipe Graphs

EMNLP 2021main

Recipe texts are an idiosyncratic form of instructional language that pose unique challenges for automatic understanding. One challenge is that a cooking step in one recipe can be explained in another recipe in different words, at a different level of abstraction, or not at all. Previous work has an…

2020

Generating Instructions at Different Levels of Abstraction

COLING 2020main

When generating technical instructions, it is often convenient to describe complex objects in the world at different levels of abstraction. A novice user might need an object explained piece by piece, while for an expert, talking about the complex object (e.g. a wall or railing) directly may be more…

Cited by 7SourcePDFScholar
2020

Normalizing Compositional Structures Across Graphbanks

COLING 2020main

The emergence of a variety of graph-based meaning representations (MRs) has sparked an important conversation about how to adequately represent semantic structure. MRs exhibit structural differences that reflect different theoretical and design considerations, presenting challenges to uniform lingui…