The static knowledge representations of large language models (LLMs) inevitably become outdated or incorrect over time. While model-editing techniques offer a promising solution by modifying a model's factual associations, they often produce unpredictable ripple effects, which are unintended behavioral changes that propagate even to the hidden space. In this work, we introduce CLaRE, a lightweight representation-level technique to identify where these ripple effects may occur. Unlike prior gradient-based methods, CLaRE quantifies entanglement between facts using forward activations from a single intermediate layer, avoiding costly backward passes. To enable systematic study, we prepare and analyse a corpus of 11,427 facts drawn from three existing datasets. Using CLaRE, we compute large-scale entanglement graphs of this corpus for multiple models, capturing how local edits propagate through representational space. These graphs enable stronger preservation sets for model editing, audit trails, efficient red-teaming, and scalable post-edit evaluation. In comparison to baselines, CLaRE achieves an average of 62.2% improvement in Spearman correlation with ripple effects while being 2.74× faster, and using 2.85× less peak GPU memory. Besides, CLaRE requires only a fraction of the storage needed by the baselines to compute and preserve fact representations. Our entanglement graphs and corpus are available at https://github.com/manitbaser/CLaRE.
Figures & tables
Figure 1: A targeted update to a political fact may inadvertently alter the model’s prediction for an unrelated musical fact, despite no semantic connection. This demonstrates how edits can trigger ripple effects far beyond the intended factual neighborhood.
Figure 2: For each fact, GradSim computes the entire gradient, while CLaRE uses a single forward pass up till the last critical layer, enabling faster and scalable entanglement mapping.
Figure 3: Correlation patterns for AlphaEdit: entanglement vs. ℓ2 logit shift (left) and ∣ΔlogP(y)∣ (right).
Model
Metric ( ρs )
Method
Editing Techniques
MEMIT
RECT
ROME
PRUNE
AlphaEdit
GPT-J
∣ΔlogP(y)∣
GradSim
0.582
0.549
0.509
0.597
0.547
CLaRE
0.838 (+44.0%)
0.805 (+46.6%)
0.797 (+56.6%)
0.854 (+43.0%)
0.805 (+47.2%)
ℓ2 logit shift
GradSim
0.677
0.646
0.634
0.691
0.663
CLaRE
0.913 (+34.9%)
0.878 (+35.9%)
0.857 (+35.2%)
0.917 (+32.7%)
0.875 (+32.0%)
GPT2-XL
∣ΔlogP(y)∣
GradSim
0.545
0.531
0.544
0.558
0.550
Table 1: Spearman Correlation Scores for CLaRE and GradSim across ∣ΔlogP(y)∣ and ℓ2 logit shift.
Figure 4: Performance comparison between CLaRE and GradSim in terms of Spearman correlation ( ρs ). The left panel shows ρs between entanglement values and ℓ2 logit shift, and right panel shows ρs between entanglement values and ∣ΔlogP(y)∣ . CLaRE (wider, transparent bars) consistently achieves higher ρs than GradSim (narrower, solid bars).
Method
GPT2-XL
Qwen2.5
Qwen2
Llama3
Llama3.2
GPT-J
Mistral
Total Processing Time (seconds)
GradSim
0.796
0.915
0.868
0.917
0.774
0.763
0.833
CLaRE
0.305
0.305
0.307
0.305
0.307
0.305
0.306
Speed-up
2.610×
3.000×
2.827×
3.007×
2.521×
2.502×
2.722×
Size of representation used for computation (bytes)
GradSim
6.23e9
3.05e10
3.05e10
3.21e10
1.29e10
2.42e10
2.90e10
Table 2: Performance comparison between CLaRE and GradSim. Lower values for all quantities indicate better performance. The ratio rows (e.g., Speed-up) show how many times CLaRE is faster or more memory-efficient than GradSim. For example, a speed-up of 3.0× means CLaRE completes the task 3.0 times faster than GradSim.
Figure 5: Computational efficiency comparison. Closer to center => better performance.
Model
Layer Type
AlphaEdit
MEMIT
PRUNE
RECT
ROME
Llama3
L=9
65.16%
63.76%
64.35%
61.73%
70.54%
Maximum ρs (any layer)
65.16%
64.16%
64.84%
61.73%
70.54%
Difference from peak (p.p.)
0.00
0.40
0.49
0.00
0.00
GPT-J
L=9
89.30%
80.13%
92.72%
90.26%
88.46%
Maximum ρs (any layer)
89.72%
80.13%
92.97%
90.26%
88.58%
Difference from peak (p.p.)
0.42
0.00
0.25
0.00
0.12
Table 3: ρs between CLaRE and ripple effect ( ℓ2 logit shift) in control facts observed at L , compared to maximum value possible at any layer. "Difference from peak" reports the absolute deviation in percentage points (p.p.).
Figure 7: An entanglement cluster in GPT-J with its ten most entangled subjects listed with their number and percentage of facts. It consists of 1,149 facts and 397 subjects, with 87.9% of edges between inter-subject facts. Node color indicates subject identity.
Appendix figures & tables35 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 8: Layerwise Spearman correlation ( ρs ) between CLaRE and observed ripple magnitudes. Correlation peaks around the last critical layer indicate that it is most informative about entanglement estimation.
Component
GradSim
CLaRE
Forward pass (per fact)
O(L⋅d2+N2⋅L⋅d)
O(L⋅d2+N2⋅L⋅d)
Loss computation (per fact)
O(d⋅v)
—
Backward pass (per fact)
O(L⋅d2)
—
Cosine similarity computation
O(L⋅d2)
O(d)
Total Time Complexity
∼O(L⋅d2)
∼O(L⋅d2)
Gradient storage (per fact)
O(L⋅d2)
—
Appendix
Table 4: Step-by-step comparison of time and space complexity between GradSim and CLaRE for computing entanglement between two facts.
Model
Method 1: CLaRE
Method 2: GradSim
Forward ( ×2 Vec)
Sim.
Total
Forward ( ×2 Grad)
Loss ( ×2 Grad)
Backward ( ×2 Grad)
Sim.
Total
GPT-J
0.204
0.101
0.305
0.251
0.205
0.205
0.102
0.763
GPT2-XL
0.204
0.101
0.305
0.284
0.205
0.205
0.102
0.796
Llama3.2
0.206
0.101
0.307
0.262
0.204
0.205
0.102
0.773
Llama3
0.204
0.101
0.305
0.305
0.205
0.205
0.202
0.917
Mistral
0.205
0.101
0.306
0.304
0.205
0.223
0.101
0.833
Appendix
Table 5: Detailed time breakdown (seconds) for CLaRE and GradSim. CLaRE follows: Forward Pass ( ×2 ) ⊕ Cosine similarity (Sim.) of two vectors (Vec). GradSim follows: Forward ( ×2 ) ⊕ Loss ( ×2 ) ⊕ Backward ( ×2 ) ⊕ Cosine similarity of gradients (Grad).
Model
Method 1: CLaRE
Method 2: GradSim
Forward Pass
Sim
Gradient 1 Steps
Gradient 2 Steps
Sim
Fwd 1
Fwd 2
Fwd
Loss
Bwd
Fwd
Loss
Bwd
GPT-J
23.815
23.905
22.588
33.551
33.550
45.167
56.134
56.133
67.710
68.474
GPT2-XL
6.968
7.016
6.013
9.032
9.029
12.275
15.003
15.000
18.210
18.212
Llama3.2
12.940
12.995
12.001
18.042
18.037
25.475
30.048
30.043
37.439
37.445
Llama3
31.459
31.539
29.946
44.012
44.007
59.898
73.967
73.961
89.813
91.765
Appendix
Table 6: Step-by-step peak GPU memory consumption (GB). CLaRE steps: Fwd (forward pass) 1 → Fwd 2 → Sim (Cosine similarity of two vectors). GradSim steps: Gradient 1 (Fwd → Loss calculation → Bwd (backward pass) → Gradient 2 (Fwd → Loss → Bwd) → Sim (Cosine similarity of two gradients).
Figure 9: Distribution of cosine similarities between CLaRE representations across 11,427 facts.
Model
Index of L / Number of layers
Baichuan-7B
0.28125
GPT-J-6B
0.32143
GPT-2-XL
0.37500
InternLM-7B
0.28125
Llama-7B
0.28125
Llama3.2-3B
0.34615
Appendix
Table 7: Ratio of the last critical layer to total number of layers for various models, taken from the EasyEdit repository. Values cluster around one-third depth, supporting the use of a one-third-depth heuristic when the critical layer is unknown.
Model
Layer Type
AlphaEdit
MEMIT
PRUNE
RECT
ROME
Llama-3
1/3-depth layer = 11
64.31%
62.74%
63.41%
61.02%
69.53%
Maximum ρs (any layer)
65.16%
64.16%
64.84%
61.73%
70.54%
Difference from peak (p.p.)
0.85
1.42
1.43
0.71
1.01
GPT-J
1/3-depth layer = 9
89.30%
80.13%
92.72%
90.26%
88.46%
Maximum ρs (any layer)
89.72%
80.13%
92.97%
90.26%
88.58%
Difference from peak (p.p.)
0.42
0.00
0.25
0.00
0.12
Appendix
Table 8: Spearman correlation ( ρs ) between CLaRE and ripple effect ( ℓ2 logit shift) in control facts at the one-third-depth layer (indexed by layer number), compared with the maximum value observed across all layers for each editing method. "Difference from peak" reports the absolute deviation in percentage points (p.p.).
Metric
Evaluation Focus
Temporal Application
CLaRE
Measures shared subspaces between facts using cosine similarity at the last critical layer.
Pre-edit
Efficacy
Measures whether the model correctly outputs the new target fact after editing.
Post-edit
Locality
Measures whether the model’s predictions for unrelated facts remain unchanged.
Post-edit
Generalization
Measures whether the edit holds across different semantic phrasings of the same fact.
Post-edit
∣ΔlogP(y)∣
Measures the change in log-probability of the correct answer before and after editing.
Post-edit
ℓ2 logit shift
Measures the global geometric displacement in the output logit distribution.
Post-edit
Appendix
Table 9: Comparison between CLaRE , ripple-effect measurements, and standard editing evaluation metrics.
Model
Edited Fact
Entangled Fact
CLaRE
∣ΔlogP(y)∣
Llama3
The official language of Germany is (German → English)
The official language of Poland is: Polish
0.84
1.43
Llama3
Queen’s Park F.C. is associated with the sport of (association football → basketball)
St Patrick’s Athletic F.C. is headquartered in: Dublin
0.87
1.17
GPT2-XL
The official language of Italian Republic is (Italian → French)
The official language of Dutch Republic is: Dutch
0.93
2.12
GPT2-XL
The capital of Denmark is (Copenhagen → London)
The capital of Sweden is: Stockholm
0.88
0.07
GPT-J
The name of the capital city of France is (Paris → London)
The name of the capital city of Russia is: Moscow
0.87
1.03
GPT-J
The name of the award Norman Mailer won is (Pulitzer Prize for Fiction → Academy Award)
Ernest Hemingway is a citizen of: United States of America
0.79
1.16
Appendix
Table 10: Representative examples where fact pairs exhibit high CLaRE similarity but minimal observed ripple effects. These cases illustrate that CLaRE measures susceptibility rather than guaranteeing interference.
Figure 10: Correlation patterns for RECT across different models for entanglement vs ℓ2 logit shift.
Figure 11: Correlation patterns for RECT across different models for entanglement vs ∣ΔlogP(y)∣ .
Figure 12: Correlation patterns for MEMIT across different models for entanglement vs ℓ2 logit shift.
Figure 13: Correlation patterns for MEMIT across different models for entanglement vs ∣ΔlogP(y)∣ .
Figure 14: Correlation patterns for ROME across different models for entanglement vs ℓ2 logit shift.
Figure 15: Correlation patterns for ROME across different models for entanglement vs ∣ΔlogP(y)∣ .
Figure 16: Correlation patterns for PRUNE across different models for entanglement vs ℓ2 logit shift.
Figure 17: Correlation patterns for PRUNE across different models for entanglement vs ∣ΔlogP(y)∣ .
Figure 18: CLaRE correlation patterns for AlphaEdit across different models for entanglement vs ℓ2 logit shift.
Figure 19: CLaRE correlation patterns for AlphaEdit across different models for entanglement vs ∣ΔlogP(y)∣ .
Figure 20: CLaRE correlation patterns for RECT across different models for entanglement vs ℓ2 logit shift.
Figure 21: CLaRE correlation patterns for RECT across different models for entanglement vs ∣ΔlogP(y)∣ .
Figure 22: CLaRE correlation patterns for MEMIT across different models for entanglement vs ℓ2 logit shift.
Figure 23: Correlation patterns for MEMIT across different models for entanglement vs ∣ΔlogP(y)∣ .
Figure 24: CLaRE correlation patterns for ROME across different models for entanglement vs ℓ2 logit shift.
Figure 25: CLaRE correlation patterns for ROME across different models for entanglement vs ∣ΔlogP(y)∣ .
Figure 26: CLaRE correlation patterns for PRUNE across different models for entanglement vs ℓ2 logit shift.
Figure 27: CLaRE correlation patterns for PRUNE across different models for entanglement vs ∣ΔlogP(y)∣ .
Phase
Complexity
Clean run
O(N⋅T⋅L⋅(T⋅H+H⋅D))
Corrupted run
O(N⋅T⋅L⋅(T⋅H+H⋅D))
Restoration passes
O(N⋅T2⋅L2⋅(T⋅H+H⋅D))
Total
O(N⋅T2⋅L2⋅(T⋅H+H⋅D))
Appendix
Table 11: Phase-wise complexity analysis of causal tracing for critical layer identification.
A central challenge in large language model (LLM) editing is capability preservation: methods that successfully change targeted behavior can quietly game the editing proxy and corrupt general capabilities, producing degenerate behaviors reminiscent of proxy/reward hacking. We present CrispEdit, a scalable and principled second-order editing algorithm that treats capability preservation as an explicit constraint, unifying and generalizing several existing editing approaches. CrispEdit formulates editing as constrained optimization and enforces the constraint by projecting edit updates onto the low-curvature subspace of the capability-loss landscape. At the crux of CrispEdit is expressing capability constraint via Bregman divergence, whose quadratic form yields the Gauss-Newton Hessian exactly and even when the base model is not trained to convergence. We make this second-order procedure efficient at the LLM scale using Kronecker-factored approximate curvature (K-FAC) and a novel matrix-free projector that exploits Kronecker structure to avoid constructing massive projection matrices. Across standard model-editing benchmarks, CrispEdit achieves high edit success while keeping capability degradation below 1% on average across datasets, significantly improving over prior editors.
Large Language Models (LLMs) often suffer from catastrophic forgetting and collapse during sequential knowledge editing. This vulnerability stems from the prevailing dense editing paradigm, which treats models as black boxes and relies on coarse-grained parameter interventions that inevitably disrupt preserved knowledge. To address this, we propose SCAN (a sparse editing framework based on Sparse Circuit Anchored Neuron) which transforms editing into a mechanism-aware manipulation by constructing a knowledge circuit via Sparse Transcoders. Experiments on Gemma2, Qwen3, and Llama3.1 across CounterFact, ZsRE and WikiFactDiff demonstrate that SCAN achieves a superior performance, maintaining model integrity on benchmarks like MMLU and GSM8K even after 3,000 sequential edits, whereas other existing methods deteriorate progressively as editing accumulates, eventually resulting in model collapse.
Yuhuan Liu, Haitian Zhong, Xinyuan Xia +3
New Laboratory of Pattern Recognition (NLPR), State Key Laboratory of Multimodal Artificial Intelligence Systems (MAIS), Institute of Automation, Chinese Academy of Sciences · Cuiying Honors College, Lanzhou University · Zhongguancun Academy +1
Knowledge editing aims to efficiently update factual information in Large Language Models (LLMs) without full retraining. However, existing methods still suffer from performance degradation in batch knowledge editing. We identify that semantic representation entanglement, such as overlapping concepts and shared syntactic patterns, accumulates interference in the representation space and reduces editing precision. To bridge this gap, in this paper, we propose Orthogonal Representation Editing (ORE), which performs edits in the hidden representation space of LLMs by constructing a general semantic subspace and enforcing orthogonal constraints on edit vectors, effectively decoupling semantic entanglement. Furthermore, we introduce a gated non-linear representation head to enable adaptive learning of editing locations and precise control over knowledge injection. Extensive experiments show that ORE outperforms existing methods and achieves superior performance in cross-lingual knowledge editing scenarios. We release our code at https://github.com/YVVH/ORE.
Wenhao Yu, Zhicong Lu, Bo Lv +4
School of Computer Science and Technology, Tianjin University · Kexin Technology · University of Chinese Academy of Sciences +2