Comparative Evaluation of LLM-Based Review Paradigms for Academic Paper Quality Assessment
Authors: Fan Huang, Hongyu Zhou
Organizations: Indiana University Bloomington, Bloomington, Indiana, USA · School of Information Resource Management, Renmin University of China, Beijing, China · Faculty of Social Sciences, University of Antwerp, Antwerp, Belgium
Growing submission volumes have renewed interest in using large language models (LLMs) to support peer review. It remains unclear how such evaluation should be structured, how much the model matters, and whether LLM scores predict research impact. We evaluate five paradigms across three input representations and three LLMs on 232 stratified ICLR 2025 submissions. Direct absolute rating matches comparative ranking on rank correlation with human scores, yet compresses most predictions above the accept threshold, flagging almost none of the papers reviewers scored below it. A base-rate-matched recalibration control locates the cause: comparative ranking supplies placement, not better ordering, and after recalibration Direct Rating reaches higher agreement than Elo while making 24% as many API calls. Abstract-only input beats full-paper summarization, and model choice matters as much as paradigm choice. Replicating on all 11,513 scored submissions reproduces these patterns, shows absolute agreement depends on the evaluated set's score spread, and finds none beating an always-reject baseline in accuracy. Human scores track citations better than any paradigm, with one exception: Group Rating retains its citation correlation after controlling for human scores, and alone ranks within the accepted pool. Ranking quality alone cannot assess review quality; calibration, thresholds, model, and target outcome all matter.
Figures & tables
Figure 1: Overview of the experimental pipeline. Papers pass through three input representations (top), then through (a) absolute rating methods, which score each paper independently, or (b) comparative rating methods, which infer a latent rating from head-to-head outcomes and rescale it to 1–10. Only the comparative family is rescaled, so inflation and other absolute-error metrics are not comparable across families. Inline metrics give the best configuration in each family on the stratified 232-paper sample at the fixed ≥6 threshold.
Paradigm
r
ρ
τ
MSE
Infl.
Direct
0.405
0.422
0.351
8.42
+2.13
Elo
0.401
0.410
0.285
4.85
+0.67
Anchor
0.353
0.369
0.300
10.35
+2.51
Group
0.405
0.388
0.279
7.87
+1.98
Swiss
0.100
0.080
0.057
6.71
+0.04
Table 1: Review paradigm comparison under abstract-only input (GPT-4o-mini). Column headings as in Table 4 . The Group row is a three-run mean (Appendix D ); all other rows are single runs.
Model
Best ρ
Best κ
Paradigm
ρ
Paradigm
κ
GPT-4o-mini
Direct
0.422
Elo
0.267
Llama 3.3-70B
Swiss
0.140
Swiss
0.060
GPT-oss-120B
Group
0.338
Group
0.161
Table 2: Best paradigm per model by ranking potential ( ρ ) and by decision utility, measured here by κ , abstract-only, 232-paper sample. The best paradigm differs by model and by criterion. Appendix N reports all fifteen configurations.
Figure 2: External validity on the 126 test papers carrying a retrievable citation count, a complete set of paradigm scores and a recorded decision. a , Paradigm rank under three evaluation targets; the lines cross, so none is best on all three. The decision target counts the 18 withdrawn submissions as non-accepted, which leaves the ordering unchanged. b , Spearman ρ with citation count, as an open circle (raw) joined to a filled circle (controlling for the mean reviewer score). Only Group Rating retains its correlation after the control ( ρ=0.304 , p=0.0006 , surviving Bonferroni correction across the eighteen tests in Table 11 ). Anchor’s partial value is negative and Swiss’s exceeds its raw value, so the two are given as positions on a common axis rather than as a decomposition.
Appendix figures & tables20 assets
Supplementary material from the paper’s appendix.
Appendix
Metric
Value
ICC(2,1) absolute agreement
0.417
Mean pairwise Spearman ρ
0.363
Mean per-paper standard deviation
0.227
Spearman ( Direct , GT)
0.204
Appendix
Table 3: Test–retest reliability of the GPT-4o-mini Direct paradigm at temperature 0.3 (three independent runs, n=11,513 papers, abstract-only). Reliability bands per Koo and Li (2016) : <0.5 poor, 0.5 – 0.75 moderate, 0.75 – 0.9 good, >0.9 excellent.
Figure 3: Population-scale false-positive (strong paper wrongly filtered) and false-negative (low-quality paper wrongly accepted) rates as a function of the accept threshold, swept from 5 to 7. The dashed gray line marks the fixed ≥6 threshold used in Table 9 ; the dotted green line marks the base-rate-matched threshold of Elo and Swiss; Direct Rating’s, at 7.67, lies beyond the plotted range. Direct Rating’s curves are flat across the plotted range because only 1.8% of its predictions fall below 7, which is why a fixed threshold at 6 makes it appear degenerate.
Figure 4: Error localization by ground-truth score bin (population scale, threshold ≥6 ). For each paradigm, blue bars show false-positive counts (strong papers wrongly filtered) and orange bars show false-negative counts (low-quality papers wrongly accepted). Direct’s errors are almost entirely false negatives, since its inflation accepts nearly all low-quality papers, whereas Elo and Swiss distribute the error budget across both classes, with false positives concentrated at borderline ground-truth scores.
Input
r
ρ
τ
Infl.
Abstract-Only
0.333
0.334
0.254
+1.46
Objective
0.193
0.180
0.137
+1.75
Vanilla
0.177
0.172
0.132
+1.72
Appendix
Table 4: Input representation compared, averaged across all five paradigms (GPT-4o-mini). r : Pearson; ρ : Spearman; τ : Kendall; Infl.: grade inflation.
Paradigm
Input
Corr.
MSE
RMSE
Acc.
Infl.
Direct
Abstract
0.405
8.42
2.90
0.134
+2.13
Group
Abstract
0.405
7.87
2.81
0.121
+1.98
Elo
Abstract
0.401
4.85
2.20
0.159
+0.67
Elo
Objective
0.357
5.31
2.30
0.159
+0.64
Anchor
Abstract
0.353
10.35
3.22
0.129
+2.51
Direct
Objective
0.276
10.79
3.28
0.125
+2.55
Appendix
Table 5: All review methods, ranked by Pearson correlation (GPT-4o-mini, 232-paper sample). Input: input representation; Corr.: Pearson r against ground truth; Acc.: exact-match rate on the rounded 1–10 score scale, which is not the binary accept/reject accuracy of Table 6 ; Infl.: grade inflation. The Group vanilla and objective rows are computed on 230 papers, two having failed group assignment; the Group abstract row is the per-paper mean of the three randomized-grouping runs and covers all 232.
Figure 5: Interaction between paradigm and input representation. Left: Spearman ρ (higher is better). Right: Mean Absolute Error (lower is better). Abstract-only consistently outperforms across paradigms, and Elo achieves the lowest MAE regardless of input representation.
Figure 6: Score distributions by input representation (all paradigms pooled, GPT-4o-mini). Violin shapes show density and box plots show quartiles; ground truth (gray) is shown for reference. The three representations differ little in spread (pooled σ 1.56, 1.62 and 1.59 for abstract-only, vanilla and objective), and all are far narrower than ground truth ( σ=2.16 ). Annotated below each group: μ (mean), σ (standard deviation), ρˉ (mean Spearman correlation with ground truth across paradigms).
Figure 7: Score distributions for the five paradigms vs. ground truth (abstract-only, GPT-4o-mini). Absolute methods (Direct, Anchor) compress scores into a narrow 6–8 range, while comparative methods (Elo, Swiss) preserve broader distributions closer to ground truth. Annotated below each: μ (mean), σ (standard deviation), ρ (Spearman correlation).
Method
Acc.
AUC
κ
Wgt. F1
Elo + Abstract
64.2
0.672
0.267
0.645
Elo + Objective
58.6
0.645
0.163
0.590
Elo + Vanilla
58.2
0.619
0.134
0.584
Direct + Abstract
42.2
0.682
0.034
0.279
Anchor + Abstract
41.8
0.640
0.029
0.270
Swiss + Abstract
56.5
0.544
0.061
0.555
Appendix
Table 6: Binary classification performance (reject/accept) on the stratified 232-paper sample. Accuracy in %; AUC is AUC-ROC on the continuous scores.
Method
@10
@20
all
Top-20 Prec.
Elo + Objective
0.752
0.757
0.933
0.700
Elo + Abstract
0.683
0.693
0.930
0.550
Anchor + Abstract
0.702
0.688
0.922
0.350
Direct + Abstract
0.669
0.691
0.926
0.000
Swiss + Abstract
0.662
0.650
0.906
0.300
Direct + Objective
0.665
0.661
0.918
0.050
Appendix
Table 7: Ordering-quality metrics for six representative methods, chosen to span the paradigms and input representations discussed in the text rather than to rank the top six on any single column. The first three numeric columns are NDCG@10, NDCG@20, and NDCG over all papers. Top- k precision is computed with a stable sort, so for paradigms that assign the same score to large blocks of papers it reports one arbitrary tie-break rather than a property of the ordering; see the discussion of Direct + Abstract below.
Figure 8: Robustness check: Spearman ρ (left) and Cohen’s κ (right) under four ground-truth aggregations, of which the trimmed mean coincides with the mean (Appendix M ). Paradigm rankings are identical across variants.
Model
Paradigm
Spearman ρ
Inflation
Cohen’s κ
Macro F1
Wgt. F1
AUC-ROC
(ranking)
(decision utility)
GPT-4o-mini
Direct
0.422
+2.13
0.034
0.330
0.279
0.682
Anchor
0.369
+2.51
0.029
0.323
0.270
0.640
Group
0.101
+2.02
0.068
0.424
0.393
0.528
Elo
0.410
+0.67
0.267
0.633
0.645
0.672
Swiss
0.080
+0.04
0.061
0.528
0.555
0.544
Appendix
Table 8: Cross-model comparison, all fifteen configurations: five paradigms × three models (abstract-only, 232-paper sample). The Group rows, including GPT-4o-mini’s, use the original score-ordered grouping (Appendix D ); the corrected GPT-4o-mini abstract-only Group run is reported in Table 1 . Three cells rest on fewer papers, where a response or a group assignment failed: GPT-4o-mini Group n=230 , GPT-oss-120B Direct n=230 and GPT-oss-120B Anchor n=228 . Table 2 summarizes the per-model best.
Figure 10: Score distributions for Direct (top row) and Elo (bottom row); the columns are, left to right, GPT-4o-mini, Llama 3.3-70B, and GPT-oss-120B. GPT-4o-mini shows clear separation between ground truth and Direct predictions (inflation), which Elo corrects. Llama 3.3-70B Direct concentrates scores at 8–9, while its Elo output spreads scores without meaningful correlation. GPT-oss-120B shows moderate spread under Direct but collapses under Elo, with 75% of papers in the single bin [5.5,6.5) and an interquartile range of 0.265, the narrowest panel here and a counterexample to the idea that comparative paradigms necessarily widen the scale.
Figure 11: Model capability profiles averaged across paradigms, on five axes: the decision utility metrics ( κ and macro F1), the threshold-free AUC-ROC, ranking potential ( ρ ), and a calibration axis plotting 1−inflation/4 so that a larger radius is better on every axis.
Figure 12: Ranking potential versus grade inflation (left) and versus decision utility (right) for all 15 configurations. GPT-4o-mini Direct sits at high ρ but near-zero κ , while Elo converts similar ρ into higher κ through calibration.
Paradigm
Threshold
Spearman ρ
Inflation
Reject recall
Accuracy
κ
Macro F1
Direct (mean of 3)
fixed ≥6
0.204
+2.20
0.5%
40.8%
0.004
0.294
base-rate matched
66.9%
57.7%
0.112
0.555
Elo (25 cmp/paper)
fixed ≥6
0.142
+0.52
61.4%
55.3%
0.076
0.538
base-rate matched
62.7%
55.6%
0.079
0.540
Swiss (14 rounds)
fixed ≥6
0.113
+0.00
80.6%
58.1%
0.061
0.511
base-rate matched
62.8%
55.6%
0.078
0.539
Appendix
Table 9: Population-scale results for GPT-4o-mini (abstract-only), at the fixed ≥6 accept threshold and at each paradigm’s own base-rate-matched threshold (the cut at which its predicted reject rate equals the true rate). Recalibration is order-preserving, so ρ and inflation are unchanged by it. ρ and inflation are computed on all 11,513 scored ICLR 2025 papers; decision metrics on the 8,655 non-withdrawn papers (true reject rate 59.5%). Direct rows use the mean of three independent runs (ICC(2,1) =0.417 ); because those scores are means of three integer ratings, Direct’s closest achievable predicted reject rate is 62.4% rather than 59.5% .
Paradigm
Threshold
Rej. rec.
Acc.
κ
Direct
fixed ≥6
0.5%
43.0%
0.004
base-rate matched
67.4%
57.5%
0.118
Elo
fixed ≥6
62.3%
55.8%
0.093
base-rate matched
61.3%
55.7%
0.095
Swiss
fixed ≥6
81.0%
57.2%
0.067
base-rate matched
63.2%
55.5%
0.085
Appendix
Table 10: Population-scale decision quality against the recorded ICLR 2025 accept/reject decisions rather than the ≥6 score rule. The qualitative pattern is unchanged: Direct Rating is reject-blind at a fixed threshold and recovers under recalibration, where it moves ahead of Elo. Under these labels Direct Rating is the one configuration whose accuracy exceeds the always-reject baseline, and only by 0.3 points.
All
Accepted
Rejected
Score
( n=126 )
( n=74 )
( n=34 )
Human review
0.568 ∗
0.430 ∗
0.408 ∗
Elo
0.308 ∗
0.101
0.410 ∗
Group
0.380 ∗
0.330 ∗
0.420 ∗
Direct
0.238 ∗
0.084
0.120
Swiss
0.165
− 0.019
0.399 ∗
Appendix
Table 11: Spearman ρ between score and citation count, overall and within ICLR decision strata. ∗ denotes p<0.05 . The human correlation survives stratification. As in Table 1 , the Group row is the per-paper mean of three randomized-grouping runs and the other rows are single runs. Group Rating is the only LLM paradigm to reach significance among accepted papers.
Operating priority
Method
Calls/paper
Reject recall
FP rate
κ
When to use
Filter aggressively
Swiss (14 rounds)
7
80.6%
74.9%
0.061
cFN≫cFP
Balanced quality filter
Elo (25 cmp/paper)
12.5
61.4%
53.8%
0.076
Best κ at the fixed cut
Minimize false rejects
Direct (mean of 3)
3
0.5%
0.0%
0.004
Equivalent to no filter
Appendix
Table 12: Operating points at the fixed ≥6 accept threshold, using population-scale numbers (Table 9 ). These are a comparison among the configurations tested, not a deployment recommendation: under base-rate-matched thresholding (Section 4.5 ) Direct Rating attains the highest κ , and no configuration here reaches the 59.5% accuracy of always rejecting. The cost ratio cFP/cFN is the relative cost of filtering a strong paper (FP) versus admitting a low-quality one (FN).
Automated peer review uses computational systems, especially language models, to assess research papers, generate feedback, and support editorial decisions.
School of Economics and Management, East China Normal University · School of Information Management, Wuhan University · China Academic Degrees & Graduate Education Development Center