multi-step-reasoning CAP-0032 · activeCarrying a chain of inference through to its conclusion
Whether a model can hold several dependent inference steps and reach the conclusion they entail, as opposed to pattern-matching the answer; failures show as correct steps with a wrong join, or shortcuts.
Tags: reasoning, general
Filed from Russ's capability map (2026-09-12). Neighbours: digit-level arithmetic is the special case where the step is a calculation; logical deduction robustness is the special case of formal deduction under distractors; this is the general competence of chaining. Claims that chain-of-thought helps or does not help a task are efficacy claims that sit under whichever capability the task exercises.
What counts as this capability
Scope boundary used when deciding whether a paper is really about this capability, rather than merely mentioning it.
In scope when the paper isolates the number of dependent steps as the variable and shows accuracy falling with it, or shows a model reaching the right answer by a route that skips required steps. NOT in scope for papers about a single reasoning domain's content (maths, logic) without the step-count variable.
Claims
- mechanismsingle paper↑1↓0For 0.6B-8B Qwen3 models on math, logic and multiple-choice reasoning, quantifying reasoning uncertainty from a directed acyclic graph built by sampling several chains and merging semantically equivalent steps with an NLI model separates correct from incorrect generations better than sequence-level entropy, likelihood and self-prompting uncertainty measures.
- observationsingle paper↑1↓0For 1.5B-7B Qwen2.5 backbones trained with RL on multi-hop retrieval QA, giving the policy reversible memory operations (summary, backtrack over a stack) with per-action process rewards raises F1 over trajectory-reward agentic-RAG baselines, and removing the two memory actions costs more than removing the planning action.
- mechanismsingle paper↑1↓0For agentic retrieval-augmented multi-hop QA with 7B-class policy models, scoring each intermediate step for both logical validity and grounding in the retrieved passages — rather than scoring steps by the final answer — yields higher EM/F1 than outcome-reward and final-answer-based process-reward training, because it removes preference pairs where flawed retrieval happened to reach the right answer.
- observationsingle paper↑1↓0When a document image states multi-step selection constraints in narrative text and the supporting numbers sit in several charts, multimodal models degrade steadily as either the number of logical hops (2 to 5) or the number of charts (2 to 6) grows, with the best model reaching 62.83% overall against over 90% for human annotators.
- observationsingle paper↑1↓0When an error is injected into a supplied chain of thought, models mostly carry it to the answer: a planted arithmetic error costs small models 50-60% accuracy and 18% on average, though the largest models lose only 3-7%; unit-conversion errors cost about 9% at every scale; skipped steps and sycophantic steps cost small models about 10%; extra correct steps cost almost nothing (0-6%).
- mechanismsingle paper↑1↓0When fine-tuning a 14B model on knowledge-graph-derived multiple-choice QA for a single medical domain, attaching supporting triples from the same source text chunk to each target triple during supervision, and repairing residual one-hop failures before reinforcement learning, gives higher accuracy on held-out 3-, 4- and 5-hop questions than training on isolated triples or running RL from an unrepaired checkpoint.
- observationsingle paper↑1↓0Having a model score its confidence step by step detects failures in multi-step reasoning better than one holistic confidence score for the whole answer, with up to 15% higher AUROC on two multi-step benchmarks, so where a chain fails is more visible per step than in the final answer.
- observationsingle paper↑1↓0For LLM agents under a fixed ReAct harness answering questions over executable database-backed APIs plus document retrieval, accuracy falls sharply as the required reasoning depth grows from 1 to 5 hops (most models lose over half their accuracy), and the surviving failures concentrate in language-mediated steps — entity disambiguation, cross-source grounding, schema alignment — rather than in emitting syntactically valid tool calls.
- mechanismsingle paper↑1↓0When a long chain of thought is verified by classifying a graph of its steps, the predictive signal comes almost entirely from the semantic content of the steps, not the graph shape: replacing step embeddings with purely structural metadata (child/parent counts, chain index, position) drops accuracy to near chance on math, science and multiple-choice reasoning, while remaining above chance only on code.
- observationsingle paper↑1↓0On natural-language logical reasoning benchmarks, auto-formalizing each reasoning step into SMT-LIB and regenerating from the first step the solver cannot verify raises both the share of solver-verified steps and final-answer accuracy over plain chain-of-thought, and greedy regeneration at the failure point beats beam search or MCTS on step verifiability.
- mechanismsingle paper↑1↓0Verifying a chain of thought by decomposing it into nodes and asking binary consistency questions per node localizes errors better than judging the whole chain at once (F1 up 10-25% over CoT-based verifiers, error-localization accuracy far above an 8-vote end-to-end judge) while using 6-58 times fewer tokens, because whole-chain judging dilutes attention and multi-sampling pays for long generations.
Techniques
- Build the reasoning graph with a local NLI model, then classprocessSplit a long chain of thought on transition keywords, link steps with entailment and contradiction edges predicted by a local NLI model instead of LLM calls, and train a graph attention network to predict whether the chain's final answer is
- Node-wise binary consistency checks for chain verificationprocessSplit a reasoning chain into dependent nodes, check each node's consistency with its inputs by a yes/no query, and report the first failing node, instead of asking a verifier to read and judge the entire chain.
- Repair one-hop gaps and add same-chunk context before RLtrainingAugments each KG triple with same-source-chunk supporting triples for supervision, then uses LLM judges to separate noisy triples from genuine one-hop knowledge gaps, continually fine-tunes on targeted repair items weighted by failure histo
- Reversible memory stack with per-action process rewardstrainingGives an RL-trained retrieval agent a LIFO memory stack with push/pop actions (plan, think, search, summary, backtrack, conclusion) and assigns format, retrieval-relevance and memory-usefulness rewards to the tokens of each action, plus bat
- Score reasoning steps for grounding, not final-answer matchtrainingTrain a generative process reward model that labels each interleaved reason/retrieve step for logical validity and evidential grounding, use it in value tree search to build step-level chosen/rejected pairs, and optimize the policy with ste
- Score uncertainty by complexity of a merged reasoning-step gdecodingSample several chains of thought, merge semantically equivalent steps into a DAG using a bidirectional-entailment NLI model, and score uncertainty by graph width, height, or propagated per-step token uncertainty.
- Stepwise self-scoring for failure detectionpromptingAfter a multi-step answer, ask the model to rate each step's correctness separately and combine the step scores, rather than asking for one confidence on the final answer.
- Verify each reasoning step with a solver and backtrack on fadecodingDecompose each generated reasoning step into context, implicit assumptions and conclusion, formalize it into a solver specification, score it by premise fidelity plus solver entailment, and regenerate from that step when the score falls bel
Sources
Every paper, post or observation behind this capability. Ones cited by a claim show the claim and its stance; ones filed directly are about the capability but have no claim drafted from them yet. Open one to add support or contest it.
- LogicTrack: Auditing Reasoning Trajectories of Large Language Models with Formal Logic Solvers2026-09-18↑ supports a claim here
- about this capability · no claim drafted yet
- about this capability · no claim drafted yet
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- LCoT-GV: Graph Attention Networks for Verifying Long Reasoning Chains in Large Language Models2026-08-31↑ supports a claim here
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- about this capability · no claim drafted yet
- ↑ supports a claim here
- Self-Evaluating LLMs for Multi-Step Tasks: Stepwise Confidence Estimation for Failure Detection2025-11-10↑ supports a claim here
- ↑ supports a claim here
Capabilities are a way of carving up the subject, and carvings are arguable. Say so if this one is wrong — especially a proposed one, which a pipeline added because several papers used the same framing, not because anyone decided it was right.