Pith. sign in

REVIEW 6 cited by

Hopping Too Late: Exploring the Limitations of Large Language Models on Multi-Hop Queries

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 2406.12775 v2 pith:3M577TGL submitted 2024-06-18 cs.CL

classification cs.CL
keywords layerslaterllmsanswerentitylatentqueriesunderstanding
verification ladder T0 review T1 audit T2 compute T3 formal
0 comments
read the original abstract

Large language models (LLMs) can solve complex multi-step problems, but little is known about how these computations are implemented internally. Motivated by this, we study how LLMs answer multi-hop queries such as "The spouse of the performer of Imagine is". These queries require two information extraction steps: a latent one for resolving the first hop ("the performer of Imagine") into the bridge entity (John Lennon), and another for resolving the second hop ("the spouse of John Lennon") into the target entity (Yoko Ono). Understanding how the latent step is computed internally is key to understanding the overall computation. By carefully analyzing the internal computations of transformer-based LLMs, we discover that the bridge entity is resolved in the early layers of the model. Then, only after this resolution, the two-hop query is solved in the later layers. Because the second hop commences in later layers, there could be cases where these layers no longer encode the necessary knowledge for correctly predicting the answer. Motivated by this, we propose a novel "back-patching" analysis method whereby a hidden representation from a later layer is patched back to an earlier layer. We find that in up to 66% of previously incorrect cases there exists a back-patch that results in the correct generation of the answer, showing that the later layers indeed sometimes lack the needed functionality. Overall, our methods and findings open further opportunities for understanding and improving latent reasoning in transformer-based LLMs.

Discussion (0). Sign in to comment.

Forward citations

Cited by 6 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. DiscoLoop: Looping Discrete Embeddings and Continuous Hidden States for Multi-hop Reasoning

    cs.CL 2026-07 unverdicted novelty 7.0 of 10

    DiscoLoop adds a discrete embedding channel to looped transformers to fix representational misalignment in two-hop reasoning, yielding near-perfect accuracy on synthetic tasks and better pretraining loss on real data.

  2. The Power of Power Law: Asymmetry Enables Compositional Reasoning

    cs.AI 2026-04 unverdicted novelty 6.0 of 10

    Power-law data sampling creates beneficial asymmetry in the loss landscape that lets models acquire high-frequency skill compositions first, enabling more efficient learning of rare long-tail skills than uniform distr...

  3. AbbIE: Autoregressive Block-Based Iterative Encoder for Efficient Sequence Modeling

    cs.LG 2025-07 conditional novelty 5.0 of 10

    An iterative Transformer that reuses its middle layers with an extra residual connection matches a standard Transformer after one pass and improves perplexity and zero-shot accuracy when run for more passes at test time.

  4. Reasoning Can Hurt the Inductive Abilities of Large Language Models

    cs.CV 2025-05 conditional novelty 5.0 of 10

    Chain-of-thought reasoning can hurt LLMs' ability to infer hidden rules from gameplay transcripts, and structured interventions recover the lost accuracy.

  5. Soft Thinking: Unlocking the Reasoning Potential of LLMs in Continuous Concept Space

    cs.CL 2025-05 conditional novelty 5.0 of 10

    A training-free method that feeds probability-weighted token embeddings back into LLMs during reasoning, improving accuracy and token efficiency on math and coding tasks.

  6. A Survey on Latent Reasoning

    cs.CL 2025-07 conditional novelty 4.0 of 10

    A survey that organizes latent reasoning methods into vertical recurrence, horizontal recurrence, and infinite-depth diffusion, arguing that silent reasoning can beat explicit chain-of-thought.

Pith tools