Fine-tuning-based knowledge editing is simple and architecture-agnostic, but standard cross-entropy increases the edited target probability without explicitly constraining changes in the non-target output distribution. In sequential editing, such unconstrained redistribution can accumulate as distributional drift and contribute to locality degradation. We propose KLOD, a bounded and distribution-preserving objective for fine-tuning-based knowledge editing that separates the intended target update from distributions that should remain stable. KLOD stops target amplification once a probability threshold is reached, while preserving the target-excluded non-target distribution at target positions and the full next-token distribution at prefix positions. Experiments on CounterFact and ZsRE with Llama3-8B-Instruct and Qwen2.5-7B-Instruct show that KLOD substantially mitigates locality degradation while maintaining high edit reliability. The target probability threshold further provides a controllable Generalization--Locality trade-off. Ablation, multi-seed, and distributional KL analyses support the interpretation that KLOD's locality gains are associated with preserving output distributions rather than simply weakening the edit. Code is available on GitHub https://github.com/Hostoday/KLOD .
Figures & tables
Model
Method
CounterFact
ZsRE
Rel.
Gen.
Loc.
Cap.
Score
Rel.
Gen.
Loc.
Cap.
Score
Llama3-8B-Instruct
pre-edit
0.87
1.18
100.00
62.11
41.04
26.00
25.26
100.00
62.11
53.34
ROME
15.42
3.73
1.00
17.52
9.42
2.40
1.98
0.26
17.22
5.47
AlphaEdit
80.33
59.40
15.80
25.46
45.25
83.41
74.78
36.10
35.28
57.39
UltraEdit
35.85
18.80
6.38
60.80
30.46
63.45
56.23
35.21
60.63
53.88
FT-L
1.37
0.40
0.00
15.07
4.21
6.96
6.58
1.03
17.88
8.11
Table 1: Main results on 3k sequential editing. Rel., Gen., Loc., and Cap. denote Reliability, Generalization, Locality, and Capability. Score is their arithmetic mean. Among editing methods, best and second-best results are shown in bold and underlined .
Method
Rewrite
Rephrase
Locality
Prompt KL
Target KL
Non-target KL
Prompt KL
Target KL
Non-target KL
Prompt KL
Target KL
ROME
16.597
14.312
14.308
15.377
13.522
13.511
15.143
13.911
AlphaEdit
3.782
8.418
5.596
3.583
6.537
5.061
3.535
4.809
UltraEdit
3.470
4.962
4.650
1.180
3.578
3.459
3.218
4.521
LocFT-BF
2.697
15.936
8.967
2.296
10.118
8.124
2.481
10.135
OVERTONE
2.635
15.266
8.680
2.181
9.698
7.794
2.378
9.729
Table 2: Distributional KL divergence after 3k sequential editing on CounterFact with Llama3-8B-Instruct. Lower values indicate smaller drift from the pre-edit model.
Dataset
Method
Rel.
Gen.
Loc.
CounterFact
KLOD
99.72±0.02
46.76±1.01
46.51±1.98
LocFT-BF
99.74±0.02
56.83±0.95
1.89±0.18
OVERTONE
99.73±0.07
57.56±0.90
1.77±0.05
ZsRE
KLOD
99.90±0.02
87.39±0.47
86.38±0.33
LocFT-BF
99.81±0.11
89.57±0.32
51.15±0.20
OVERTONE
99.78±0.16
88.75±0.30
51.25±0.25
Table 3: Mean ± standard deviation over three Breadth-First training seeds with Llama3-8B-Instruct. The sampled 3k edit set and all hyperparameters are fixed.
Figure 1: Generalization–Locality trade-off across target probability thresholds α on CounterFact with Llama3-8B-Instruct. The α=1.0 endpoint is clipped to 1−10−6 when computing the logit-odds margin.
Method
Rel.
Gen.
Loc.
Cap.
KLOD
99.70
47.37
44.75
60.77
w/o Lprefix (w/ Lnt )
99.60
52.05
41.30
60.70
w/o Lprefix (w/ Lfull )
99.73
53.72
32.90
57.72
w/o Lnt
99.70
52.70
9.15
60.78
w/o Lprefix,Lnt
99.72
61.73
2.02
44.24
w/o All
99.77
55.83
1.87
41.92
Table 4: Ablation study on CounterFact with Llama3-8B-Instruct. Lfull denotes a full-vocabulary KL at target positions, including the target token, used in place of Lnt . w/o All corresponds to LocFT-BF with standard cross-entropy.
Figure 2: Effect of pre-edit target prior on Lnt . (a) Distribution of pθ0(a1∣x) . (b) Mean paired Locality gain across target-prior quartiles. Error bars and Q1–Q4 intervals are normal-approximation 95% CIs ( n=750 per quartile).
Target objective
Rel.
Gen.
Loc.
Thresholded CE
99.80
46.20
37.50
Logit-odds hinge (KLOD)
99.70
47.37
44.75
Table 5: Matched-Generalization comparison between KLOD and sequence-level thresholded cross-entropy on CounterFact with Llama3-8B-Instruct.
Figure 3: Scaling behavior on ZsRE from 3k to 150k sequential edits. KLOD maintains Rel. and Gen. comparable to LocFT-BF while substantially improving Loc. across edit scales with Llama3-8B-Instruct.
Method
Llama3-8B
Qwen2.5-7B
CounterFact
ZsRE
CounterFact
ZsRE
ROME
7.68
8.46
6.71
8.50
FT-L
1.60
1.70
0.34
1.00
LocFT-BF
0.16
0.23
0.17
0.30
KLOD
0.37
0.55
0.43
0.62
Table 6: Average editing time per edit in the 3k sequential editing setting. KLOD adds modest overhead over LocFT-BF while remaining under one second per edit.
Appendix figures & tables13 assets
Supplementary material from the paper’s appendix.
Appendix
α
λprefix
λnt
Rel.
Gen.
Loc.
0.85
0.8
0.6
100.00
87.66
88.35
0.85
1.2
0.4
100.00
88.04
88.51
0.75
1.2
0.6
100.00
85.03
88.60
0.85
1.2
0.6
100.00
87.77
88.48
0.95
1.2
0.6
100.00
89.75
88.56
0.85
1.2
0.8
99.95
85.50
88.86
Appendix
Table 7: One-at-a-time sensitivity analysis on the held-out 500-example ZsRE set. The bold row denotes the shared configuration used in the main experiments.
Hyperparameter
Llama3-8B
Qwen2.5-7B
Editable layer
22
6
Editable module
MLP down-proj
MLP down-proj
α
0.85
0.85
λnt
0.6
0.6
λprefix
1.2
1.2
Batch size
100
100
Appendix
Table 8: Implementation hyperparameters for KLOD.
Model
Dataset
Multi-token targets
Token Rel.
Strict Rel.
Llama3-8B
ZsRE
2,313/3,000 (77.1%)
99.85
99.61
Qwen2.5-7B
ZsRE
2,313/3,000 (77.1%)
99.90
99.57
Llama3-8B
CounterFact
40/3,000 (1.3%)
100.00
100.00
Qwen2.5-7B
CounterFact
40/3,000 (1.3%)
100.00
100.00
Appendix
Table 9: Reliability evaluated exclusively on multi-token target examples. Strict Rel. requires all target positions in an example to predict the gold token correctly.
Method
Edits
Rel.
Gen.
Loc.
Cap.
Score
FT-M
500
100.00
99.90
1.50
22.70
56.02
1k
99.95
99.75
1.30
15.33
54.08
3k
0.67
0.63
0.45
32.35
8.53
AlphaEdit
500
82.10
43.70
20.20
19.71
41.43
1k
88.05
55.30
20.10
18.87
45.58
3k
0.00
0.00
0.07
17.53
4.40
Appendix
Table 10: Cumulative edit-scale analysis on CounterFact with Qwen2.5-7B-Instruct.
Method
Rewrite
Rephrase
Locality
Prompt KL
Target KL
Non-target KL
Prompt KL
Target KL
Non-target KL
Prompt KL
Target KL
ROME
8.019
7.917
7.440
8.651
8.071
7.521
8.095
6.430
AlphaEdit
12.919
12.981
12.949
12.669
12.157
12.130
13.293
12.962
UltraEdit
0.702
6.030
1.690
0.228
3.999
1.218
0.188
2.985
LocFT-BF
4.106
16.573
10.200
2.672
9.980
8.491
3.463
10.746
OVERTONE
3.959
16.391
10.259
2.482
9.646
8.381
3.396
10.863
Appendix
Table 11: Distributional KL divergence after 3k sequential editing on CounterFact with Qwen2.5-7B-Instruct. Lower values indicate smaller distributional drift from the pre-edit model. Best values are shown in bold . We use the same evaluation protocol as Table 2 .
Method
Component
Mean
Median
P90
P95
P99
KLOD
Prompt
0.099
0.063
0.226
0.306
0.513
Non-target
0.364
0.168
0.808
1.342
3.119
LocFT-BF
Prompt
2.475
2.324
3.957
4.535
5.588
Non-target
8.567
8.369
12.671
14.234
16.718
OVERTONE
Prompt
2.379
2.225
3.776
4.312
5.366
Non-target
8.257
8.015
12.350
13.930
16.298
Appendix
Table 12: Instance-level KL distributions after 3k sequential edits on CounterFact with Llama3-8B-Instruct. Prompt aggregates rewrite, rephrase, and locality contexts, whereas Non-target aggregates target-position KL from rewrite and rephrase contexts after target-token exclusion and renormalization. Lower values indicate less distributional drift.
Target objective
Preservation
Rel.
Gen.
Loc.
Cap.
CE
Full KL
99.77
54.22
22.55
51.47
CE
Non-target KL
99.77
54.42
26.77
54.11
Logit-odds hinge
Full KL
99.73
53.72
32.90
57.72
Logit-odds hinge
Non-target KL
99.60
52.05
41.30
60.70
Appendix
Table 13: Controlled no-prefix ablation on CounterFact with Llama3-8B-Instruct.
Method
Rel.
Gen.
Loc.
Cap.
KLOD
99.89
86.85
86.47
61.42
w/o Lprefix
99.97
88.67
81.26
60.92
w/o Lnt
99.57
87.99
82.09
61.68
w/o Lprefix , Lnt
99.92
89.25
50.93
61.78
w/o All
99.93
89.21
51.24
62.10
Appendix
Table 14: Ablation study on ZsRE with Llama3-8B-Instruct. The row without both preservation terms uses only the bounded logit-odds objective. The w/o All variant corresponds to LocFT-BF with the standard cross-entropy objective.
Setting
Loc.
Damage
F
O
CounterFact
Bounded only
2.02
97.98
18.95
79.03
+Lnt
41.30
58.70
13.57
45.13
Full KLOD
44.75
55.25
12.02
43.23
ZsRE
Bounded only
50.93
49.07
0.094
48.974
Appendix
Table 15: Post-hoc decomposition of locality prediction changes with Llama3-8B-Instruct. F denotes flips to edit-target tokens, and O denotes all other prediction changes. For ZsRE, F and O are reported to three decimal places because target flips are rare.
Method
Rel. EM
Gen. EM
Cap.
pre-edit
0.00
0.20
62.11
AlphaEdit
66.60
52.20
25.46
LocFT-BF
99.80
53.00
41.92
OVERTONE
99.60
56.40
42.51
KLOD ( α=0.85 )
99.60
48.00
60.77
KLOD ( α=1.0 )
99.60
61.60
57.65
Appendix
Table 16: Free-running generation results on 500 CounterFact cases after 3k edits with Llama3-8B-Instruct. Rel./Gen. EM denote normalized exact match on rewrite/rephrase prompts; bold marks the best edited-model result in each column.
Method
Rel.
Gen.
Loc.
Cap.
LocFT-BF
99.93
96.21
35.22
61.83
OVERTONE
99.90
95.98
34.98
61.62
KLOD
99.75
93.11
56.30
61.30
Appendix
Table 17: Results after 3k edits on WikiBigEdit with Llama3-8B-Instruct.
λnt
Rel.
Gen.
Loc.
Cap.
0.2
99.70
48.23
35.33
60.98
0.4
99.63
47.43
40.37
60.78
0.6
99.70
47.37
44.75
60.77
0.8
99.63
45.07
47.42
61.07
Appendix
Table 18: Sweep over λnt with λprefix fixed at 1.2 on CounterFact with Llama3-8B-Instruct.
λprefix
Rel.
Gen.
Loc.
Cap.
0.5
99.77
48.37
44.25
60.88
0.9
99.77
47.27
44.75
60.85
1.2
99.70
47.37
44.75
60.77
1.5
99.73
46.20
44.97
60.68
Appendix
Table 19: Sweep over λprefix at the primary operating point, with λnt=0.6 and α=0.85 , on CounterFact with Llama3-8B-Instruct.