Papers for

natural language engineers

Papers whose findings have a practical use for this group, as judged from the abstract. Open a paper to read what it means in practice.

Confidence anchored decoding improves masked diffusion language models

Cord: Confidence-Anchored Order Residual Decoding for Masked Diffusion Language Models

Abstract: The decoding order of masked diffusion language models (dLLMs) can substantially affect generation quality, yet common decoders typically apply the same reveal rule throughout generation. Confidence provides a strong default, but it measures how decisively a position can be predicted now, not how useful revealing that position will be for subsequent decoding. We propose Cord, a lightweight prompt-conditioned policy that retains confidence decoding as a stable reference and learns when and how to depart from it through geometric residuals over generation direction, proximity to revealed context, and two-sided infilling. The residuals adapt to both the prompt and the evolving partial response. Rather than sampling a new policy action at every decoding step, Cord samples a single low-dimensional coefficient matrix per rollout, which induces an entire state-dependent reveal trajectory. This yields a contextual-bandit formulation trained directly from sequence-level rewards, without step-level credit assignment or backbone updates. Across three dLLMs and five reasoning, code, and constraint-satisfaction benchmarks, Cord improves average task success from 32.0% under confidence decoding to 48.2%, and further improves over the best per-domain fixed residual. Behavioral audits show that the learned residuals induce substantial, task-dependent changes in reveal locality and two-sided infilling. Cord adds only $0.53$M trainable parameters, requires no additional backbone forward passes, and incurs only 5.39% inference latency overhead.

Thu 29 OctComputation and LanguageArtificial Intelligence
The gist
Deciding the order in which parts of a sentence get filled in matters a lot for language models that generate text by masking and revealing words. The standard way picks the most confident guesses first, but that doesn’t always help later steps. The authors created Cord, a small system that smartly adjusts this order based on the prompt and what's already been written, learning a kind of plan for revealing words all at once. This method improves how well these models solve tasks like reasoning or coding, without needing much extra computing power.
Open → 2610.39372v1

Language model weekday concepts behave as points not smooth circles

Spokes, not a Ring: Revisiting the Weekday Manifold in Language Models

Abstract: Recent work has hypothesised that large language models may represent some concepts as multi-dimensional manifolds instead of single directions. Using these manifolds to interpret or steer representations often assumes that moving along them corresponds to a continuous change in the represented concept. In this work, we test this continuous manifold assumption on the prototypical weekday manifold. Despite its striking circular geometry, we find that the weekday representations behave more like seven discrete states arranged in a circle than a continuous ring. First, we show that local sensitivity has seven minima aligned with the weekdays, producing a step-like mapping between representation and behaviour under on-manifold steering. Second, we test whether any concepts are represented along the manifold outside the seven discrete states, and find neither time of day, uncertainty, nor natural text populate the intermediate space. Together, these results challenge the continuous interpretation of the weekday manifold and motivate testing whether movement along other representation manifolds correspond to meaningful changes in model representations and behaviour.

Tue 27 OctMachine LearningArtificial Intelligence
The gist
The authors looked at how large language models represent the idea of weekdays. People thought weekdays might be stored as a smooth circle where you could slide gradually from Monday to Tuesday and so on. But the authors found weekdays are actually stored as seven separate points arranged in a circle, not a smooth ring. This means the model’s understanding jumps between distinct days instead of changing continuously.
Open → 2610.37796v1

Different language models share similar text representations without merging weights

Five Architectures, One Shared Space Cross-Model Representational Alignment Without Weight Merging

Abstract: Combining language models is usually done by averaging weights, which works only when the models share a common starting point. We ask whether five frozen, independently trained models with different internal designs (four transformers from four organizations and one state-space model) can be related through their activations alone, with no weight merging. Using permutation tests, an independent replication probe set, depth sweeps, pooling ablations and confound checks, we find statistically robust correspondence between how the five models organize the same text. It is strongest at each model's final layer and weaker for the state-space model, whose weakest pairing is still 35-43 times chance. We use this to build a shared space with Generalized Procrustes Analysis, in which no model is a fixed reference. At the final layer, mean held-out retrieval accuracy over the twenty ordered model pairs is 0.91 to 0.93 on two probe sets (chance 0.03), beating pairwise linear maps (0.82 to 0.85), but the space is worse than those maps in the middle layers. It transfers to ordinary English of unfamiliar grammatical form and fails on mathematical and logical notation. We then test whether the space supports a router that picks among the five models on gradeable tasks. Across four task types we find no case where routing beats always using the strongest model, and we report this as a negative result. A correctness signal that looked strong turned out to be category membership in disguise. All experiments ran on one laptop without a GPU.

Sat 24 OctComputation and Language
The gist
Combining different language models usually requires mixing their internal settings, which only works if they start in the same way. This paper shows that five very different models, trained separately, still represent text in surprisingly similar ways. The researchers created a way to align these representations without changing the models’ settings, especially near the final output. However, this shared space doesn’t improve choosing between models for tasks, and it struggles with math or logic texts.
Open → 2610.33495v1

Community archive offers ethically sourced dataset of 5 million social posts

The Community Archive: An Ethically Sourced X (Twitter) Dataset

Abstract: We present The Community Archive, a novel dataset of over 5 million posts from the social media site X (previously known as Twitter). In contrast with other large scale social media datasets, which are generally assembled without user consent via web scrapers, The Community Archive uses an opt-in model to obtain author consent for every post in the dataset. This enables us to release both the metadata and the content of users' posts at a previously unprecedented scale. Our dataset supports work in a wide variety of domains, including social network analysis, narrative tracking, and diachronic language modeling. We demonstrate the utility of our dataset by conducting a sample analysis of content-based homophily in our network.

Wed 21 OctSocial and Information Networks
The gist
Many social media datasets are collected without asking users for permission, which raises privacy and ethical concerns. The authors created The Community Archive, a large dataset of over 5 million posts from X (formerly Twitter) where each user gave consent before their content was included. This allows researchers to access both user posts and related data ethically and at a scale that was not possible before. They showed how this dataset can be used to study how similar people connect in social networks.
Open → 2610.30392v1

Language models struggle more when combining multiple tasks in one prompt

On the Fragility of Tasks under Composition: Implicit Budgeting in Language Models

Abstract: Modern language models are increasingly asked to handle several tasks within a single prompt. Doing so requires solving each task correctly while integrating the resulting answers into a coherent response. In this paper, we identify a fundamental limitation in this process, where models make substantially more errors when tasks are composed, even when they can solve every constituent task reliably in isolation. This degradation cannot be fully explained by the accumulation of independent errors. Across both open-weight models and the frontier model Claude Opus 5, our findings instead point to an implicit thinking budget underlying this effect. In particular, under composition, models use substantially fewer tokens per task than in isolation, even when the full sequence remains well within the context window. Tasks that require longer solution traces in isolation are consequently more $\textit{fragile}$ under composition, i.e., models make more errors on prompts containing these tasks. In isolation, non-fragile tasks receive more reasoning than they need and waste compute. However, by grouping tasks according to their fragility, the implicit budgeting can be manipulated to reduce token usage by $43$\% across a range of math and linguistic tasks while also preserving accuracy.

Mon 19 OctComputation and LanguageArtificial IntelligenceMachine Learning
The gist
Language models can handle tasks well when given separately but make more mistakes when asked to do several tasks together in one prompt. This problem is not just because errors add up; instead, models seem to share a hidden token 'budget' that they spend less per task during combined tasks. Tasks needing longer reasoning are especially fragile and suffer more errors when combined. The authors show that by grouping tasks based on this fragility, it's possible to reduce token use significantly without losing accuracy.
Open → 2610.27190v1

Programs guide fast reasoning in frozen judgement language models

ABACUS: Program-Guided Multistep Reasoning over Frozen Judgment Models

Abstract: Judgment models answer semantic questions by scoring a finite set of candidate outcomes. Can reusable programs turn these local decisions into powerful multistep reasoning? We introduce \method, a framework that jointly constructs judgment schemas and composition programs for frozen judgment models. A generative teacher designs the procedure offline; the judgment model resolves local semantic questions online, and the saved program composes its decisions into an answer. We study three allocations of design effort between humans and the teacher, focusing on construction through a shared interface. We instantiate the framework with Kev. On three selected BIG-Bench Hard tasks, nine independently constructed programs solve all 450 executions of 150 development inputs. A separate deployment study freezes three programs after development-set reference-agreement refinement and evaluates them on 600 held-out questions. These programs achieve near-perfect 99.67\% macro accuracy, versus 64.00\% for direct Kev and 68.80\% for final-answer-only Qwen3.5-4B. They attain comparable observed accuracy to Qwen's unrestricted response policy (99.07\%) with an \textbf{8.43-fold online speedup}: 0.255 versus 2.150 seconds per question. These results show how reusable programs can substantially expand the reasoning capability of a compact judgment model while keeping its parameters fixed.

Mon 19 OctArtificial Intelligence
The gist
Large language models often decide answers by scoring possible options, but combining these small decisions for complex reasoning is tough. The authors present ABACUS, a method that uses fixed "judgment models" together with reusable programs to build step-by-step reasoning processes efficiently. Their approach shows improved accuracy and much faster response times on hard language tasks compared to direct answers from the models. This means complex reasoning can be done more reliably and quickly without changing the underlying model itself.
Open → 2610.25963v1

DeltaTrace assigns clear support or opposition scores to language tokens

DeltaTrace: Efficient Signed Attribution for Reasoning Language Models

Abstract: We study how words in the context support or oppose a language model's response and present DeltaTrace, a novel attribution framework that explains the effect of input tokens on a fixed model response. DeltaTrace measures how the response's log-probability changes when the context tokens being explained are masked. To distribute this difference among source tokens, it constructs operator-specific local rules for finite changes and composes them backward through the computational graph using effective secant slopes. Each token is assigned a signed attribution as the inner product of its embedding displacement and the corresponding backward-propagated slope. Local conservation makes these contributions sum to the measured score difference and preserves their meaning when aggregated over sentences or passages. DeltaTrace supports both attention and linear-attention models, with auxiliary memory growing linearly with sequence length at fixed model dimensions and chunk size. On the evaluated attention model, DeltaTrace achieves the lowest deletion-faithfulness scores (RISE and MAS) on most retrieval and reasoning tasks and the highest needle-in-a-haystack Recall, exceeding FlashTrace by 5.67-24.33 percentage points. On the evaluated hybrid attention and linear-attention model, DeltaTrace lowers RISE on 9 tasks and MAS on 12 relative to FlashTrace.

Mon 19 OctMachine Learning
The gist
When language models generate answers, it's important to know how each word in the input helped or hurt the result. The authors introduce DeltaTrace, a method that measures how removing each word changes the confidence in the model’s answer. It assigns positive or negative scores to each word, explaining their influence consistently and efficiently for different types of language models. This helps understand and trust model decisions better, especially in tasks that require reasoning or finding specific information.
Open → 2610.25877v1

Language models learn grammar from indirect examples in training data

Where's the Indirect Evidence? Investigating Grammatical Generalization with Influence Functions

Abstract: Language models generalize beyond their training corpus to learn linguistic phenomena (Patil et al., 2024; Misra and Mahowald, 2024), showing that there exists indirect evidence driving learning. Prior work has inferred that indirect evidence exists without identifying its character or considered specific hypotheses about what it might be. We explore an alternative bottom-up method for identifying indirect evidence. We use influence functions (Koh and Liang, 2017) to measure how individual training sentences affect model predictions in 15 grammatical phenomena from BLiMP (Warstadt et al., 2020). We filter out a phenomenon's direct evidence using hand-constructed rules and take the 60,000 most influential remaining sentences as indirect evidence. This indirect evidence substantially affects learning: retraining without it lowers held-out accuracy more than removing a matched random group for every phenomenon across five models (by a median of 12 points). We characterize the indirect evidence by its similarity to our direct evidence filters: it (partially) meets the filters' structural conditions at a median of 4.7 times the rate of a matched random group. Finally, clustering phenomena by indirect-evidence overlap recovers three of the five BLiMP categories that include multiple phenomena, suggesting that this method can reveal linguistic relationships.

Fri 16 OctComputation and LanguageMachine Learning
The gist
Language models can understand grammar rules even when those rules aren’t shown directly in their training examples. The authors used a technique called influence functions to find which training sentences affected the model’s grammar predictions the most. They discovered that many important sentences didn’t contain direct examples of the grammar but still helped the model learn indirectly. This finding helps explain how language models grasp complex language patterns from indirect clues.
Open → 2610.22919v1

Diffusion language models linked to quantum systems enable new text generation methods

Diffusion Language Models as Open Quantum Systems

Abstract: Diffusion language models generate text by reversing a classical diffusion process over token sequences. We show that their continuous-time forward and reverse dynamics can be embedded in the framework of open quantum systems, which describes quantum systems interacting with their environment. This connection provides a basis for extending diffusion sampling to superpositions of sentence states and for modifying the underlying generation dynamics. We construct a $τ$-leaping unraveling scheme that simulates stochastic trajectories of these states while updating multiple token positions at each step. This enables generation conditioned on superposed prompts or thoughts, which we call Superposition of Prompts (SoP) and Superposition of Thoughts (SoT). The same formulation yields Quantum-Inspired Remasking (QIR): perturbing the masked-diffusion dynamics produces a confidence-based rule for revising previously generated tokens. Experiments with pretrained diffusion language models show that superposition-based generation can retain information from conditioning components not selected at the final measurement, while QIR improves LLM-assessed text quality when applied at an appropriate stage of generation.

Thu 15 OctMachine LearningComputation and Language
The gist
Generating text in AI often involves reversing a process that gradually adds noise to words until they become random. The paper shows that this process can be thought of like how quantum systems interact with their surroundings. This new way lets the model handle multiple possible prompts or ideas at once, like thinking about several sentences simultaneously. It also introduces a method to revise earlier parts of the text more confidently. Tests with existing language models show these ideas can keep extra information and improve text quality when used properly.
Open → 2610.21672v1

Discrete diffusion models adapt efficiently to sparse categorical data

Discrete Diffusion Models are Minimax Optimal Under Sparsity

Abstract: Discrete diffusion models have emerged as a leading alternative to autoregressive models for generating text and other categorical data, yet their theoretical foundations remain less developed than those of their continuous counterparts. For continuous diffusion models, a prominent line of theory suggests that these models can adapt to low-dimensional structure in the data, thereby improving statistical efficiency and generalization. In this work, we investigate the discrete analogue of this phenomenon by studying the statistical rates of discrete diffusion models under sparsity assumptions. By analyzing a nonparametric estimator derived from a regularized score-entropy objective, we establish minimax-optimal rates in the sparse regime. The proposed regularization can be viewed as an adaptation of label smoothing techniques introduced for classification, and does not require the knowledge of the sparsity parameter. This shows that discrete diffusion models can adapt intrinsically to sparsity.

Tue 13 OctMachine Learning
The gist
Generating text and other data with many categories is challenging, especially when the data has underlying simple patterns. The paper shows that a type of model called discrete diffusion models can automatically adapt to such simplicity—or sparsity—without needing to know how simple the data is beforehand. The authors mathematically prove that their approach achieves the best possible accuracy in this sparse setting. This means these models work well not just in practice but also have solid theoretical guarantees.
Open → 2610.19020v1

Multilingual language models show weak universal color perception patterns

Probing the Geometry of Color Representations in Multilingual Language Models

Abstract: Do multilingual language models learn a universal internal geometry for color, and is it perceptually grounded or primarily linguistic? We decompose color representations into two geometric axes: (P1) alignment to perceptual color space, and (P2) cross-lingual symmetry. Analyzing layerwise embeddings across models and multilingual datasets, we find that perceptual grounding is weak: alignment to CIE-LAB peaks in intermediate layers, then collapses toward output layers. Cross-lingual symmetry degrades with depth, suggesting later layers encode language-specific structure. Functionally, we show that geometric properties predict task performance: models achieve 96.7% accuracy on color classification at layers where P1 alignment peaks, with P1 alignment (r=0.70) significantly correlating with downstream capabilities. Our results reveal a dissociation: text-only LMs learn universal color-language geometry, not universal color-perception geometry, providing diagnostics for where perceptual structure is preserved in language models.

Tue 13 OctComputation and LanguageMachine Learning
The gist
This paper looks at how language models that understand many languages think about colors. The authors found that these models do not strongly learn how humans perceive colors but do have some common way of organizing color information across languages. The part of the models that best matches human color perception is in the middle layers, but this fades away near the end. They also found that how well the model aligns with human color perception relates to how accurate it is at naming colors.
Open → 2610.18331v1

Transformer activations reveal stable meaning across paraphrases using math tools

Gluing Local Contexts into Global Meaning: A Sheaf-Theoretic Decomposition of Transformer Representations

Abstract: Existing interpretability tools do not test whether a representation keeps the same content when only the phrasing changes. We treat each paraphrase pair as a local witness that two activations should agree and build a cellular sheaf over the paraphrase graph; its Laplacian $L_\mathcal{F}$ answers the question on a frozen model with no training. The kernel $H^0$ is a content subspace: at 20 dimensions it beats the preserved subspace of the concept eraser LEACE on held-out CounterFact fact retrieval across eight architectures by a mean $+17.1$\,pp, and constraining all paraphrases of a fact jointly adds a further $+6.5$\,pp. The spectral complement concentrates causal influence: ablating the most paraphrase-variable coordinates, a coordinate-wise proxy for it, changes model outputs $5.6$ to $26.5\times$ more than ablating coordinates of matched per-coordinate variability, across nine models from 124M to 13B parameters. Stacking layers into a grid creates $b_1 = N(L-1)$ algebraic 1-cycles, and the resulting model-derived harmonic mass varies by nearly three orders of magnitude across six architectures and ranks them as their steering fragility does (Spearman $ρ= 0.90$, exact one-sided permutation $p = 0.014$). The same paraphrase graph yields the content subspace, the influence directions, and the fragility measure. Project page: https://cwru-aism.github.io/gluing-lc-page/

Mon 12 OctComputation and LanguageMachine Learning
The gist
Understanding whether a language model keeps the same meaning when sentences are reworded is tricky. The authors use a branch of math called sheaf theory to connect different paraphrased phrases and find parts of the model’s inner workings that hold consistent meaning. They show this method works better than earlier techniques at identifying stable content and also helps locate the model parts most responsible for changing outputs. This approach can measure how fragile different model designs are when faced with changes in phrasing.
Open → 2610.17117v1

Large language models use culture and practice to do language

Communication, Vocalisation, and Language

Abstract: The contention is that the current batch of Large Language Models don't *understand* language, but they *do* it. Rather than LLMs forming some kind of ``distributed representation'' of symbols, the claim is that LLMs are capturing ``Cultural Intelligence'' and grounding symbols in what the sociologists call practices.

Mon 12 OctComputation and Language
The gist
The paper argues that large language models (LLMs) don't truly understand language like humans do. Instead of forming mental images or ideas of words, these models learn language by capturing shared cultural behaviors and social practices. This way, LLMs perform language tasks by imitating the way people use symbols within their communities. The authors suggest this is how these models 'do' language without deep comprehension.
Open → 2610.16490v1

Causal fate dynamics track influence beyond immediate effects

Causal-fate dynamics of unrealized influence

Abstract: Many dynamical systems generate influences whose consequences are not fully exhausted in the realized trajectory at the moment they arise. Such consequences are often treated as absent, delayed or statically stored, leaving unclear how unrealized influence retains future relevance as the system evolves. Here we formulate causal-fate dynamics, in which generated influence may be realized, remain latent, or be transformed by subsequent dynamics, and give an exact finite-transport representation when the relevant maps are specified. A connectome-constrained Caenorhabditis elegans model first motivates the biological hypothesis that unresolved inter-neuronal influence may persist and contribute to later propagation; it does not establish such a mechanism in living animals. We next examine operational Internet routing, where a dynamically updated cross-observer history retains predictive information beyond the current local route state. We then use the representation to construct a Transformer architecture that explicitly transports and selectively realizes latent contextual influence while retaining language-modeling function. The three studies distinguish a model-motivated scientific hypothesis, an observational phenomenon compatible with future-relevant history and an executable construction for carrying unrealized influence through subsequent computation.

Thu 8 OctMachine Learning
The gist
Sometimes, actions or events in complex systems have effects that don’t show up right away, but still shape what happens later. The authors propose a new way to think about and model these delayed or hidden influences, calling it causal-fate dynamics. They test their ideas in three areas: a worm neural network model, Internet routing data, and a new design for a language model that keeps track of past hidden influences. This helps explain how information from the past can still matter as systems change and evolve.
Open → 2610.11422v1

Text representations can look uniform but hide sequence details

Isotropic Yet Undecodable: The Sequential Content-Sufficiency Gap in Latent-Predictive Text Representations

Abstract: We study sequential content sufficiency by investigating whether a representation retains the ordered target information available in its input. An information-theoretic decomposition separates input ambiguity, representation loss, and readout mismatch. We construct recoverable views where perfect agreement and joint isotropic Gaussianity coexist with zero target information, and establish limits imposed by deterministic canonical anchors. Token log-loss provides a one-sided information-loss bound; a fixed-penalty ridge analysis shows why rank alone cannot determine prediction risk. These results motivate CANOPE, a nonautoregressive framework with ordered latent canvases, canonical-token supervision, and geometric regularization. On 40,000 validation sequences, latent-agreement (PL0) and token-grounded (PL2) have nearly identical pooled ranks but reach 13.5% and 98.8% positional Recall@1, respectively, under strong natural corruption when the correct target length is provided. On 3,930 LJSpeech validation utterances, frozen PL2 with a trained MatchaTTS readout yields 21.54% word error rate (WER) on corrupted text, versus 99.22% for frozen PL0, while end-to-end MatchaTTS reaches 10.93%. These results show that geometric regularity alone does not guarantee recoverable sequential content or effective downstream access in the text settings studied here.

Tue 6 OctArtificial IntelligenceComputation and LanguageMachine Learning
The gist
This paper investigates if certain text representations keep the order of words intact. The authors show that some representations can appear perfectly regular but actually lose the sequential information needed to recover the original text. They develop a new method called CANOPE, which improves how well ordered information is preserved and accessed. Experiments with corrupted text confirm that just having regular geometric properties does not guarantee good recoverability of word order.
Open → 2610.07906v1

Shared memory improves test-time training for AI models

Universal Test-Time Training

Abstract: Recent Test-Time Training (TTT) architectures compress context into fast weights that are updated online and queried as memory. Existing TTT designs keep this memory private to each layer: it recurs only over time, and depth merely indexes L separate memories. We argue that memory ownership need not be tied to depth, and introduce Universal Test-Time Training (uTTT), in which all layers read and write one shared memory while retaining layer-specific backbone parameters. The shared memory thus recurs over two dimensions, time and depth, with chunks and layers as their units: a write by a deep layer in one chunk can be read by a shallow layer in the next. We instantiate this idea as uTTT-MoE and uTTT-Dense. uTTT-MoE routes each token head to a few experts in a pool shared by all layers; uTTT-Dense applies the whole shared memory at every layer without routing. In language modeling, uTTT-MoE reaches 15.5 and 27.9 RULER accuracy at 124M and 760M, 2.6 and 2.1 points above its layer-private counterpart at equal state and active compute, the highest among tested bounded-state models, with per-token loss matching or beating full attention. In novel view synthesis, sharing at fixed per-layer compute gains 0.92 dB in view-23 object PSNR in routed models and 0.76 dB in dense models.

Sun 4 OctMachine LearningComputation and LanguageComputer Vision and Pattern Recognition
The gist
Test-Time Training helps AI models adapt as they work, by updating a memory of recent information. Previous methods kept separate memories for each layer in the model, but the authors show that sharing one memory across all layers works better. This shared memory lets different parts of the model learn from each other's updates, improving results in language tasks and image synthesis. Their approach achieves higher accuracy and better image quality than methods with separate memories.
Open → 2610.05484v1

Regularization choices improve models generalizing to longer texts

Length Generalization Needs Proper Regularization

Abstract: Length generalization is the ability of sequential models to perform well on context lengths unseen during training. In this work, we show that the challenge of achieving length generalization is related not only to architectural choices such as positional encoding and the attention mechanism but also to the training procedure itself. We study how regularization affects length generalization and find that weight decay can hinder extrapolation. In contrast, dropout improves extrapolation when its placement within the architecture is reconsidered. In that regard, we show that the standard placement of dropout before layer normalization introduces a systematic distributional mismatch, and that applying dropout just before the linear projection resolves this issue. For example, a modified SmolLM3 with sliding window attention, continually pre-trained with dropout, can extrapolate perfectly to 64$\times$ on Needle-in-a-Haystack and far beyond the pre-training context size on RULER and HELMET. Mamba2 also benefits from dropout, suggesting an architecture-agnostic nature of the problem. We further propose Variance-Preserving Affine Dropout (VPAD), a new dropout strategy that substantially reduces the resulting pre-activation variance mismatch, leading to further extrapolation improvements in transformers.

Sat 3 OctMachine Learning
The gist
Many AI models that read and understand text struggle when asked to work with much longer pieces than they were trained on. The authors found that not only the model design but also how the models are trained affects this ability. They showed that using weight decay can actually harm the model’s skill in handling longer inputs, while using dropout in smarter places helps it do better. They proposed a new way to apply dropout that further improves performance on texts far longer than seen during training.
Open → 2610.04518v1

Local mixing layers help transformers understand word order over long texts

How Local Mixing Encodes Relative Position in Global NoPE Attention

Abstract: The attention operation is naively position invariant. However, positional information is fundamental to natural language, and therefore a variety of explicit position encodings have been developed in transformer-based models, such as rotary position encoding (RoPE). Although explicit position encodings have long been assumed to be required, recent methods that interleave local mixing layers, such as sliding window attention (SWA) and gated linear attention, while not encoding position (NoPE) in global attention layers has recently been shown to be successful at scale. How and why this approach works is not well-understood. In this paper, we develop an explanation of how hybrid models of this sort can implicitly encode position at global NoPE layers. Supported by both theoretical and empirical evidence, our central argument is that SWA and gated linear attention induce a recency bias in the residual stream that propagates to, and is selected by, the global attention logits. Moreover, in contrast to the implicit position encodings found in models with only global NoPE attention, in which positional information arises solely from the causal mask, the recency bias in hybrid models can be maintained across long sequences. In addition to deepening our understanding of how hybrid models encode position, these findings may provide insights for how to encode position in a way that can extrapolate to longer sequence lengths indefinitely.

Tue 29 SeptComputation and LanguageArtificial IntelligenceMachine Learning
The gist
Transformers are computer models that read and write language, but they usually need special clues about word order to make sense. The paper explains how mixing small chunks of words locally inside the model helps it remember the order even without those special clues. This creates a bias towards recent words that the model can use globally to understand position and meaning. Their findings help explain why some new transformer designs work well and might help design models that read longer texts better.
Open → 2609.38109v1

Language models use fewer context tokens when focusing attention

Retrieval Capacity of Self-Attention Under Competition

Abstract: How many tokens from its context does a language model actually use, and what determines that number? We study this question through self-attention. Without retraining, we retain only the tokens with the highest attention weights at each head, layer, and query, keeping their original weights unchanged. By varying the selected set size and measuring the increase in negative log-likelihood (NLL), we estimate the effective attention set size needed to stay within a chosen loss tolerance. Relatively small selected sets can keep NLL close to the full-attention baseline, although the required size varies across models. Attention-based selection substantially outperforms random selection. Selected sets exhibit geometric structure, although geometric separation alone does not establish that model loss is preserved. Extending context while evaluating the same prediction targets increases the required set size, while its fraction of context decreases over the tested range. Experiments with a fixed supporting fact show that additional background pushes its tokens down the attention ranking and reduces their attention mass. Renormalizing the retained weights can substantially reduce the required set size, showing that it also depends on how selected representations are combined. Conditional theoretical models explain how competition and attention-mass retention can produce growing set sizes without more distinct information to retrieve. These results provide a way to measure effective attention set size in language models and investigate its dependence on context, competition, and aggregation.

Tue 29 SeptComputation and LanguageMachine Learning
The gist
Language models look at many words when trying to understand text, but they don’t always use all of them equally. The authors find that by only keeping the tokens (words or pieces of words) that get the most attention, the model performs almost as well as when using all tokens. The number of important tokens changes depending on the situation, and the way the model combines them matters too. They also created a theory to explain why models need more tokens in some cases even when no new information appears. This helps us understand how language models decide what context to use when predicting text.
Open → 2609.37879v1

Enhanced mixture-of-experts improve few-step diffusion language models

E-MoE: Enhanced Mixture-of-Experts for Non-Factorized Diffusion Language Models

Abstract: Masked diffusion models (MDMs) generate sequences by progressively unmasking several tokens per denoising step, but their reverse process is typically factorized over positions, limiting sample quality in the few-step regime where diffusion's speed advantage over autoregressive decoding matters most. A recent line of work introduces a continuous Gaussian latent, trained as a variational autoencoder, to capture correlations across positions, but such approaches are prone to posterior collapse, where the latent is silently ignored. We propose Enhanced Mixture-of-Experts (E-MoE), which builds the reverse process as a mixture of factorized distributions over a discrete shared latent given by the expert-routing decisions of a Mixture-of-Experts (MoE) backbone, without increasing active parameters over the factorized baseline. Across synthetic multi-modal benchmarks, binarized MNIST, and LM1B, E-MoE improves few-step generation over factorized baselines.

Tue 29 SeptComputation and Language
The gist
Generating sequences of words quickly and accurately is challenging for some language models, especially when they try to predict multiple words at once. The authors found that previous methods that treated each word independently limited quality when generating sequences in just a few steps. They introduced a new approach called Enhanced Mixture-of-Experts (E-MoE), which combines multiple expert models to better capture the relationships between words during generation. This approach improves the quality of generated text without needing more computational power than before.
Open → 2609.37533v1

Data aware rotary encoding improves token order understanding in transformers

RoPE is Dead, Long Live RoPE: Towards Scalable Data-aware Positional Encodings

Abstract: Transformers process tokens without any inherent notion of order, making positional encoding a fundamental requirement rather than an architectural refinement. Rotary Position Embedding (RoPE) has become the default positional encoding in modern language models, yet it is heavily biased toward nearby tokens. Existing alternatives have been evaluated under different settings, leaving the literature fragmented and without a clear replacement. We bring structure to this landscape by examining a specific weakness of RoPE: its slow frequency bands, whose wavelengths exceed the training context and expose models to unseen angles during extrapolation. We therefore introduce Data aware RoPE (DaRoPE), which preserves standard RoPE on the fast bands but replaces absolute position on the slow bands with bounded coordinates learned from contextual representations. Therefore, the slow-band geometry depends on the data rather than only on positional distance. We compare representative encodings under matched conditions across synthetic tasks, symbolic music, genomics, neural signals, and language models spanning 124M to 50B parameters. Across these experiments, DaRoPE leads on non-text benchmarks, mitigates recency bias, while remaining best or on par in language modeling and length extrapolation. Moreover, the learned coordinates also make the mechanism interpretable, revealing how attention layers leverage contextual information beyond token distance. Together, these results support DaRoPE as the best overall default among the evaluated methods, when there is no domain-specific reasons to prefer another.

Mon 28 SeptComputation and LanguageMachine Learning
The gist
Transformers need a way to know the order of words or tokens because they process them without built-in order. The existing common method, RoPE, struggles with long-distance positions beyond the training context, making some predictions less accurate. The paper introduces DaRoPE, which keeps the strengths of RoPE for close tokens but learns positions differently for tokens far apart, based on the data context. This approach works better for sequences like music, DNA, and neural signals, and matches or beats RoPE in language tasks too.
Open → 2609.34556v1

A unified theory explains how people learn concepts and chunks

A Unified Account of Concepts and Chunks

Abstract: Cognitive psychology has studied how people encode, use, and learn concepts that describe categories, and how they represent, recognize, and acquire chunks for familiar patterns of elements. The literatures on these two topics are nearly disjoint, which poses a challenge for unified theories of cognition. In this paper, we review Cobweb, a computational account of categorization and concept formation, and propose an extended theory that incorporates chunks and their acquisition. The theory makes no commitments about modality, applying to any experience that decomposes into elements and relations among them. We also present \trellis/, an implementation of this theory, and illustrate its application to learning context-free grammars, which we adopt as a testbed because they involve both concept-like and chunk-like elements. In addition, we report experimental results on three synthetic grammars that demonstrate the system's ability to represent syntactic knowledge, use it to parse and generate sentences, and learn compositional structures from sample parses. We conclude by discussing related work on concepts and chunks, along with directions for future research in the area.

Thu 24 SeptComputation and LanguageArtificial Intelligence
The gist
People learn by recognizing categories (concepts) and familiar patterns (chunks), but these ideas have been studied separately. The authors review a system called Cobweb that models how concepts form, and they extend it to include chunks too. They created a tool named Trellis to test this idea using grammar rules, showing it can learn language-like patterns from examples. This work helps understand how we combine different kinds of knowledge in our minds.
Open → 2609.30414v1

Arabic dialect bias causes worse language model performance on sa'idi

Some Dialects Are More Equal Than Others: Non-Prestigious Arabic Dialectal Bias in LLMs

Abstract: Previous work on Egyptian Arabic in NLP has focused largely on the prestigious Cairene Egyptian Arabic (CEA) dialect, resulting in a lack of representation for the less prestigious Sa'idi Egyptian Arabic (SEA) dialect both in LLM and resource development. Does this lack of representation influence an LLM's view of the acceptability of SEA (upstream), and does an upstream bias against SEA lead to worse performance (downstream)? We investigate the upstream effect of SEA dialectal features on LLM preferences in a Targeted Syntactic Evaluation (TSE) task which reveals a significant bias against SEA across multiple LLMs. We then analyze the effect of these same features on downstream model performance on MMLU benchmarks and show that models experience a degradation in performance when presented with SEA. This work highlights the need for further exploration on how sub-dialectal variation impacts language technologies.

Mon 21 SeptComputation and Language
The gist
Many AI language models understand Egyptian Arabic mainly through its common urban dialect, Cairene Egyptian Arabic, while the rural Sa'idi dialect is rarely represented. The authors found that this lack of exposure causes these models to prefer Cairene features over Sa'idi ones, even when Sa'idi usage is correct. This bias lowers the model's performance on tasks involving Sa'idi Arabic, showing that not all dialects are treated equally by current language technology. The study points to the need to better include and support dialects like Sa'idi in language AI.
Open → 2609.23955v1

Quantum circuit improves paraphrase detection with fewer parameters

Parameter-Efficient Quantum NLP for Paraphrase Detection: Performance, Robustness, and Entanglement

Abstract: Rigorous empirical validation of quantum machine learning on natural language tasks remains scarce. We evaluate a 10-qubit hybrid quantum-classical variational circuit (2,148 parameters) for paraphrase detection across three benchmarks: MRPC, Quora Question Pairs (QQP), and adversarial PAWS. On QQP (n = 10 seeds), the circuit achieves 75.53% +/- 0.75%. accuracy, statistically outperforming parameter-matched classical baselines (DeepMLP: p = 0.015, Cohen's d = 1.20; F1: p < 0.001, d = 2.32) and surpassing DistilBERT-4bit with 31,191 fewer parameters. On MRPC the optimal 2-layer variant reaches 92% of BERT-base accuracy at 54,000 lower parameter cost. Circuit depth analysis reveals a dataset-depth scaling effect; entanglement analysis via the Meyer-Wallach measure identifies multi-qubit entanglement as the primary performance driver (r = 0.85 across four variants). Adversarial evaluation on PAWS reveals emergent robustness: 98.2% recall versus 81.6% classical (+16.6 pp, d = 1.24, p < 0.001), without adversarial training. These results constitute the first systematic parameter-matched multi-benchmark empirical validation of hybrid variational circuits for NLP. All results are from classical simulation; hardware validation is future work.

Sun 13 SeptComputation and Language
The gist
Detecting when two sentences mean the same thing is an important task in language understanding. The authors show that a special kind of quantum-inspired computer model can do this task well using fewer adjustable parts than common classical methods. Their model is also more resistant to tricky examples designed to fool it, even without extra training. This work uses simulated quantum circuits to compare performance, with future work planned on real quantum hardware.
Open → 2609.14529v1

Type diversity helps transformers understand language structure better

Type Diversity Enables Transformers to Generalise Compositionally

Abstract: Compositional generalisation has been divided into lexical and structural generalisation. Previous work has found that structural generalisation is harder than lexical for Transformers. We propose that this difference is not inherent to Transformers, but due to the high diversity of lexical types and low diversity of structural types in the specific datasets of these previous works. By type diversity we mean the number of different constructors of that type, instead of, for example, the specific word combinations that might populate the structure. To test this, we vary the amounts of type diversity of lexical and structural types in previously published datasets. We create linguistically diverse variants of the COGS and SLOG datasets using Grammatical Framework. We find that type diversity correlates with compositional generalisation equally in lexical and structural test cases, supporting our hypothesis. We note a contradiction with the proposition in previous work that compound divergence explains the difficulty in compositional generalisation tasks. We further investigate the effects of other dataset properties on compositional generalisation, such as the diversity of types other than the novel test structure, and surface properties of the logical semantics format.

Fri 11 SeptComputation and Language
The gist
Transformers, a type of artificial intelligence, often struggle to understand new ways that words and sentence structures are combined. The authors found that this difficulty isn’t because of a built-in limitation, but rather because previous tests used datasets with less variety in sentence structures compared to word types. By creating new datasets with more balanced variety in both words and structures, they showed that transformers can actually learn new patterns equally well. They also questioned earlier ideas about what makes these tasks hard and looked into other factors that might affect learning.
Open → 2609.13144v1

Visual grounding helps small language models learn object properties better

Augustinian BabyLM: What Ostensive Definition Can and Cannot Teach a Small Language Model

Abstract: A language model normally begins training with random word embeddings: whatever 'banana' means must be learned from training corpora. I implement St. Augustine's picture of word learning, meaning by ostension, for a small masked language model (DeBERTa) trained on 10M words: before training, visually grounded tokens receive embeddings derived from the image regions they label; other tokens start random. Visual initialization leaves a measurable imprint that lasts until the end of training. At the same time, the effect remains invisible under most BabyLM benchmarks, which probe abstract grammatical knowledge: visual initialization does not affect performance there. The only zero-shot exception is object-property knowledge (COMPS, Misra et al. 2023), where seeding helps in every configuration. To follow up on this result, I build a corpus-tailored version of the Visual-Property Swap benchmark (Lin et al., 2026), which tests color, material, size, and shape knowledge, with per-item training frequency and seeded status. Here, vision-seeded models have a persistent, seed- replicated advantage, confined to the seeded words. As a causal test, I show that synthetic grounding of previously unseeded words transfers the advantage to exactly those words. Function words and abstract vocabulary also receive strong visual seeds and retain them throughout training, and the training objective draws on them: held-out mask-prediction loss falls for these words in every seed. However, no benchmark I run registers this. What evaluation would pick this up remains an open question.

Thu 10 SeptComputation and Language
The gist
This paper tests whether giving a small language model some visual clues about word meanings before training helps it learn better. The researchers gave image-based starting points for some words related to objects, like colors and shapes, then trained the model on a text dataset. They found that this visual seeding helped the model remember and predict properties of specific objects better, but it did not improve general grammar or abstract language skills. The paper raises the question of what kinds of tests would detect the benefits this kind of visual grounding provides.
Open → 2609.11870v1

Bangla dialect benchmark aligns transliteration with multiple annotations

5-Dialects-BN: Unmasking the Impact of Transliteration on Bangla Dialectal LLMs

Abstract: Large Language Models (LLMs) have achieved remarkable progress across natural language processing (NLP) tasks, yet their capabilities degrade sharply for low-resource languages and dialectally diverse settings. Bangla, the world's sixth most spoken language, exemplifies this gap: existing resources overwhelmingly target Standard Bangla, leaving its regional dialects without the benchmarks needed to develop or evaluate dialect-aware systems. We address this gap with 5-Dialects-BN, the first multi-annotation Bangla dialect benchmark to align Romanized transliteration with dialectal text, Standard Bangla, English, and subjectivity labels across five regional varieties. The dataset comprises 6,000 manually annotated entries spanning five major dialects: Chittagong, Barisal, Noakhali, Sylhet, and Rangpur (Chittagong 1,900; Noakhali 1,500; Sylhet 1,200; Barisal 700; Rangpur 700), reflecting natural online availability. Each entry is enriched with five aligned annotations: the original dialectal text, a Romanized transliteration, an English translation, a Standard Bangla translation, and a subjectivity label (subjective vs. objective). Annotations were produced and cross-validated by native speakers and undergraduate linguistics students to ensure dialectal authenticity and semantic fidelity. The resulting resource supports a diverse suite of tasks, including dialect identification, dialect-to-standard normalization, machine translation, subjectivity classification, and parameter-efficient fine-tuning (e.g., LoRA) of multilingual LLMs. By providing a standardized, multi-annotation benchmark, 5-Dialects-BN enables principled evaluation of LLMs on dialectally diverse Bangla and lays a foundation for further research in low-resource, dialect-aware NLP.

Wed 9 SeptComputation and Language
The gist
Bangla is a widely spoken language with many regional dialects, but most language technology focuses only on the standard version. The researchers created a new dataset called 5-Dialects-BN that includes texts from five Bangla dialects, along with their Romanized versions, English and standard Bangla translations, and labels indicating if the text is subjective or objective. This resource helps improve and test language models on these diverse dialects, supporting tasks like dialect recognition and translation. It is verified by native speakers to ensure accuracy and dialect authenticity.
Open → 2609.09964v1