SYNTHESIS NOTE
Topics›Natural Language Inference›this note

Do language models really understand meaning or just surface frequency?

Explores whether LLMs comprehend semantic meaning independently of textual frequency, or whether high-frequency paraphrases systematically outperform rare ones even when meaning is identical across math, translation, and reasoning tasks.

Synthesis note · 2026-05-02 · sourced from Natural Language Inference

Adam's Law (TFL) generalizes a previously local finding into a global property of LLM computation. The earlier NLI work showed predicates in entailment hypotheses skew higher-frequency than premises, and that fine-tuning amplifies rather than dilutes this bias — see Does fine-tuning on NLI teach inference or amplify shortcuts?. Adam's Law extends this across four task families: math reasoning, machine translation across hundreds of language pairs, commonsense reasoning, and agentic tool calling. The constant: when meaning is held fixed and only surface form varies, the higher-frequency paraphrase outperforms the lower-frequency one.

The mechanism is straightforward but uncomfortable. Higher-frequency text occurred more often during pre-training, so it sits in a denser, better-modeled region of the distribution. The model's "comprehension" is therefore not meaning-recognition first and surface-decoding second — it is statistical-mass recognition first, with meaning emerging downstream of that recognition. This converges with Can models pass tests while missing the actual grammar?: correct outputs do not certify that meaning is what the model is tracking.

The pattern matters because paraphrase invariance is a load-bearing assumption almost everywhere LLMs are deployed. We assume the same prompt, said two ways, will yield the same answer. Adam's Law says no: it will yield the frequency-weighted answer, and the surface form is a covariate of accuracy, not a transparent vehicle for the request. This also shadows the output side. Do different AI models actually produce diverse outputs? documents convergence in what models say; Adam's Law documents the same convergence in how models comprehend what is said to them. Both endpoints of the prompt-response loop pull toward the corpus mean. Frequency is not noise around meaning. Frequency is a substantial fraction of what comprehension means inside a transformer.

Inquiring lines that read this note 91

This note is a source for these research framings, grouped by the broader line of inquiry each explores. Scan the bold lines of inquiry; follow any specific question forward.

Why do multiple language models independently generate similar outputs? Can we reliably distinguish AI-generated from human-written text? Do language models learn underlying linguistic structure or merely surface patterns? What distinguishes genuine understanding from correct linguistic performance? Does learning articulatory physics explain speech communication superiority? Can language models develop genuine communicative grounding with humans? What systematic failures occur in human preference-based model evaluation? What explains the gap between LLM semantic understanding and production? What reasoning limitations and biases do language models systematically exhibit? Do language models truly understand their encoded knowledge or merely retrieve patterns? How do diffusion language models compare to autoregressive architectures? What fundamental limitations prevent embeddings from solving task-relevant retrieval? How do benchmark scores relate to real-world task completion? Does reasoning fine-tuning trade off other critical model abilities? Does chain-of-thought reasoning faithfully reflect actual model reasoning processes? Why doesn't LLM knowledge translate to improved reasoning outputs? How can we determine if computational systems are genuinely conscious? Do language models genuinely understand or primarily match statistical patterns? How do mechanistic features and representations drive model behavior? Can prompts override training-embedded biases in language models? Does reasoning architecture matter more than model scale? Does training data format shape reasoning more than domain content? How do pretraining data composition and task diversity shape reasoning? Does semantic diversity improve reasoning quality in reinforcement learning? Can scaling alone produce compositional generalization in neural networks? What defense strategies address attacks that per-skill scanning cannot detect? Can formal verification substitute for human understanding of AI proofs?

Related concepts in this collection 3

This note in its neighbourhood — explore the map, then jump to a related concept in the list below.

Concept map
13 direct connections · 105 in 2-hop network ·medium cluster Open in graph ↗

Click a node to walk · click center to open · click Open in graph to see this note in the full knowledge graph

your link semantically near linked from elsewhere

Related papers in this collection 8

Papers most semantically related to this note, ranked by cosine similarity in the embedding space.

Original note title

high-frequency phrasing wins — LLMs systematically prefer textually frequent paraphrases over rare ones with the same meaning