Efficient Conformal Calibration for Paired Recommendation Decisions
Organizations: Antai College of Economics and Management Shanghai Jiao Tong University, Shanghai, China · Meta
Abstract
Risk control can suppress useful changes to a frozen recommendation rule. We study how to recover valid activation from the same observed fractional losses. Two specified internal calibrators can lose efficiency by compressing losses into their sum or clipping auxiliary inverse counts before averaging. We propose Averaged Conformal Risk Calibration, or ACRC, which averages before clipping. A product identity proves expected-risk validity, while pointwise bounds characterize the additional activation. For fixed populations sampled without replacement, we connect activation to signed utility under heterogeneous users and switching constraints. Near the budgets, positive population mean gain and the stated nondegeneracy conditions give positive leading-order utility increments despite sampling dependence. Across six datasets, changing only calibration improves discounted net utility by over raw and over RB. A separately frozen Jester confirmation gives over raw with the rule and filter fixed, using a five-seed approximate 95 percent paired interval. Against information-matched SCoRE selecting risk or reward scores, the mean utility difference is . These gains use more mean realized risk within the declared budgets. Upstream failures delimit the benefit: efficient calibration releases useful modifications when the proposals themselves have value.
Figures & tables
| Set. | Calibrator | |||
|---|---|---|---|---|
| A | Raw | |||
| RB | ||||
| ACRC (ours) | ||||
| B | ACRC (ours) | |||
| SCoRE, risk prediction | ||||
| SCoRE, reward ratio |
| Dataset | Model | Top20 | PerK [ 15 ] | UMC [ 16 ] | SCoRE/PerK [ 6 ] | SCoRE/UMC [ 6 ] | ACRC (ours) |
|---|---|---|---|---|---|---|---|
| KuaiRec | LG | 0.0067 | 0.0066 | 0.0471 | 0.0066 | 0.0074 | 0.0085 |
| X | 0.0086 | 0.0114 | 0.1438 | 0.0088 | 0.0118 | 0.0122 | |
| SIG | 0.0162 | 0.0162 | 0.0220 | 0.0162 | 0.0148 | 0.0104 | |
| KuaiRand | LG | 0.0006 | 0.0008 | 0.0260 | 0.0013 | 0.0007 | 0.0007 |
| X | 0.0014 | 0.0022 | 0.0264 | 0.0022 | 0.0015 | 0.0015 | |
| SIG | 0.0003 | 0.0005 | 0.0380 | 0.0005 | 0.0003 | 0.0005 |
Appendix figures & tables34 assets
Supplementary material from the paper’s appendix.
Appendix
| Cohort | Model | Observed | Expected bound | Observed | Expected bound |
|---|---|---|---|---|---|
| shared | LightGCN | 0.02060 | 0.01994 | 0.007015 | 0.008328 |
| XSimGCL | 0.01935 | 0.01948 | 0.006632 | 0.007360 | |
| SIGformer | 0.01762 | 0.01898 | 0.006378 | 0.007226 | |
| full | LightGCN | 0.02024 | 0.01996 | 0.007067 | 0.008644 |
| XSimGCL | 0.01964 | 0.01971 | 0.006855 | 0.007853 | |
| SIGformer | 0.01964 | 0.01955 | 0.006795 | 0.007463 |
| Domain | Source version | Positive label | Interaction split and duplicate handling | Minimum |
|---|---|---|---|---|
| KuaiRec | KuaiRec 2.0 small matrix | Watch ratio | Keep the earliest observation per pair. A label-blind global permutation assigns 10% to training, 10% to validation, and 80% to held-out feedback. | 20 |
| KuaiRand-random | KuaiRand-Pure | Official click label | Split the April 8–21 standard log globally in time into 80% training and 20% validation. Use the April 22–May 8 random log for held-out feedback. Keep the earliest pair in each log and remove all historical pairs from the random log. | 20 |
| Music | SIGformer-released Music benchmark | Rating | Retain the released training, validation, and test splits of 34,915, 4,986, and 9,974 pairs. No within-split duplicate or cross-split overlap is present. | 2 |
| Epinions | SIGformer-released Epinions benchmark | Rating | Retain the released training, validation, and test splits of 289,645, 41,376, and 82,753 pairs. No within-split duplicate or cross-split overlap is present. | 2 |
| MovieLens-25M | Complete official ML-25M release | Rating | Use all 25,000,095 ratings. Unique pairs are sorted within each user by timestamp, with item-ID tie breaking, and split chronologically into 80% training, 10% validation, and 10% held-out feedback. | 40 |
| Data | Training users | Items | Eligible | Common | |
|---|---|---|---|---|---|
| KuaiRec | 1411 | 3185 | 1411 | 1211 | 611 |
| KuaiRand | 24231 | 7004 | 12626 | 10213 | 9613 |
| Music | 3472 | 2498 | 2066 | 1145 | 545 |
| Epinions | 17894 | 17660 | 13206 | 9382 | 8782 |
| ML-25M | 162205 | 35015 | 14041 | 13618 | 13018 |
| Dataset | ||||
|---|---|---|---|---|
| KuaiRec | ||||
| KuaiRand | ||||
| Music | ||||
| Epinions | ||||
| ML-25M | ||||
| Jester |
| Dataset | Model | NDCG@20 | Recall@20 | Length | ||
|---|---|---|---|---|---|---|
| KuaiRec | LG | |||||
| X | ||||||
| SIG | ||||||
| KuaiRand | LG | |||||
| X | ||||||
| SIG |
| Dataset | Model | SCoRE/PerK | SCoRE/UMC | ACRC (ours) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| KuaiRec | LG | 0.2242 | 0.000827 | 0.000093 | 0.2278 | 0.010583 | 0.000122 | 0.5391 | 0.016667 | 0.000206 |
| X | 0.2464 | 0.015507 | 0.001013 | 0.2499 | 0.011773 | 0.000136 | 0.5221 | 0.016547 | 0.000195 | |
| SIG | 0.6812 | 0.000055 | 0.000012 | 0.6791 | 0.010530 | 0.000123 | 0.7543 | 0.015014 | 0.000172 | |
| KuaiRand | LG | -0.4883 | 0.000552 | 0.005961 | -0.4977 | 0.003047 | 0.002622 | -0.4846 | 0.007583 | 0.009855 |
| X | -0.5008 | 0.000487 | 0.006042 | -0.5113 | 0.003403 | 0.003096 | -0.4977 | 0.009244 | 0.009944 | |
| Dataset | Backbone | Method | NDCG | Recall | |||
|---|---|---|---|---|---|---|---|
| ML-25M | LightGCN | MIR [ 17 ] | |||||
| ACRC (ours) | |||||||
| XSimGCL | MIR [ 17 ] | ||||||
| ACRC (ours) | |||||||
| SIGformer | MIR [ 17 ] | ||||||
| ACRC (ours) |
| Dataset | Backbone | Method | NDCG | Recall | Length | |||
|---|---|---|---|---|---|---|---|---|
| ML-25M | LightGCN | Raw | ||||||
| RB | ||||||||
| ACRC (ours) | ||||||||
| XSimGCL | Raw | |||||||
| RB | ||||||||
| ACRC (ours) |
| Dataset | Backbone | Combination vs. MIR | vs. raw | vs. RB |
|---|---|---|---|---|
| ML-25M | LG | |||
| X | ||||
| SIG | ||||
| KuaiRand | LG | |||
| X | ||||
| SIG |
| Dataset | Model | Comparator | ACRC (ours) | External | External | External | ||
|---|---|---|---|---|---|---|---|---|
| KuaiRec | LG | SCoRE/U | 1.3167 | 0.5391 | 0.2309 | +0.308189 | 0.016655 | 0.000191 |
| X | Top20 | fixed | 0.5221 | 0.2532 | +0.268899 | 0.000000 | 0.000000 | |
| SIG | PerK | fixed | 0.7543 | 0.6812 | +0.073020 | 0.000055 | 0.000012 | |
| KuaiRand | LG | SCoRE/P | 1.3551 | -0.4846 | -0.4836 | -0.000992 | 0.000766 | 0.009852 |
| X | SCoRE/P | 1.4101 | -0.4977 | -0.4954 | -0.002220 | 0.000694 | 0.009937 | |
| SIG | SCoRE/P | 1.3282 | -0.4555 | -0.4573 | +0.001813 | 0.000762 | 0.009632 |
| Proposal | Metric | ACRC (ours) | SCoRE | |||
|---|---|---|---|---|---|---|
| Original features | Augmented default | Augmented tuned | Feature selection | |||
| Selected proposal | ||||||
| Within-Top20 reranking | ||||||
| Dataset | Model | risks | SCoRE risks | |||
|---|---|---|---|---|---|---|
| KuaiRec | LightGCN | |||||
| XSimGCL | ||||||
| SIGformer | ||||||
| KuaiRand | LightGCN | |||||
| XSimGCL | ||||||
| SIGformer |
| Calibrator | |||
|---|---|---|---|
| ACRC (ours) | |||
| SCoRE risk prediction | |||
| SCoRE reward ratio, default | |||
| SCoRE reward ratio, | |||
| SCoRE both score families, |
| Dataset | Control | LightGCN | XSimGCL | SIGformer |
|---|---|---|---|---|
| KuaiRec | raw | |||
| RB | ||||
| KuaiRand | raw | |||
| RB | ||||
| ML-25M | raw | |||
| RB |
| Domain | Both below | One near | Both near | Any above |
|---|---|---|---|---|
| Jester | ||||
| KuaiRand | ||||
| KuaiRec | ||||
| MovieLens | ||||
| Music | ||||
| Epinions |
| Dataset | ||||||
|---|---|---|---|---|---|---|
| KuaiRec | 0.249 | 0.857 | 0.021 | 0.201 | ||
| KuaiRand | 0.068 | 0.983 | 5.475 | 0.599 | ||
| Music | 0.009 | 0.358 | 0.189 | 0.008 | ||
| Epinions | 0.036 | 0.524 | 0.205 | 0.028 | ||
| ML-25M | 0.100 | 1.074 | 1.037 | 0.334 | ||
| Jester | 0.096 | 0.866 | 0.859 | 0.234 |
| Method | Risk | Mean | Exceedance % | 99th percentile | Maximum |
|---|---|---|---|---|---|
| raw | 0.01113 | 2.08 | 0.02097 | 0.02566 | |
| 0.00448 | 6.19 | 0.01119 | 0.01352 | ||
| RB | 0.01129 | 2.11 | 0.02107 | 0.02571 | |
| 0.00462 | 7.58 | 0.01162 | 0.01545 | ||
| ACRC (ours) | 0.01249 | 6.64 | 0.02374 | 0.02951 | |
| 0.00498 | 10.72 | 0.01236 | 0.01602 |
| Proposal | |||
|---|---|---|---|
| Selected proposal | |||
| Within-Top20 reranking | |||
| Pool reranking | |||
| PerK proposal | |||
| UMC proposal |
| Calibration sample size | Risk budgets | Loss resolution | ||||||
|---|---|---|---|---|---|---|---|---|
| Interval | Dataset | LightGCN | XSimGCL | SIGformer |
|---|---|---|---|---|
| A Unadjusted | KuaiRec | |||
| KuaiRand | ||||
| Music | ||||
| Epinions | ||||
| ML-25M | ||||
| B Bonferroni | KuaiRec |
| Dataset | Model | Ungated | ACRC (ours) | ||||
|---|---|---|---|---|---|---|---|
| KuaiRec | LG | 0.5814 | 0.018759 | 0.000233 | 0.5391 | 0.016667 | 0.000206 |
| X | 0.5561 | 0.018546 | 0.000219 | 0.5221 | 0.016547 | 0.000195 | |
| SIG | 0.7621 | 0.017043 | 0.000191 | 0.7543 | 0.015014 | 0.000172 | |
| KuaiRand | LG | -0.4182 | 0.020338 | 0.066605 | -0.4846 | 0.007583 | 0.009855 |
| X | -0.4360 | 0.021081 | 0.061804 | -0.4977 | 0.009244 | 0.009944 | |
| SIG | -0.4200 | 0.020456 | 0.041176 | -0.4555 | 0.012247 | 0.009640 |
| Pool | Higher/tie/lower | |||||
|---|---|---|---|---|---|---|
| 0.25 | 80 | +0.002220 | 14/1/0 | +0.04796 | 0.008987 | 0.002876 |
| 0.50 | 80 | +0.004828 | 14/1/0 | +0.05685 | 0.010754 | 0.003821 |
| 1.00 | 160 | +0.010821 | 15/0/0 | +0.07856 | 0.011896 | 0.004462 |
| 40 | +0.007526 | 15/0/0 | +0.05933 | 0.012104 | 0.004410 | |
| 80 | +0.009959 | 15/0/0 | +0.06914 | 0.012042 | 0.004444 | |
| 2.00 | 80 | +0.009301 | 15/0/0 | +0.07793 | 0.013235 | 0.005351 |
| Dataset | Zero gains | |||
|---|---|---|---|---|
| KuaiRec | 128/600 | 0.12143 | 0.035643 | 0.29354 |
| KuaiRand-random | 0/600 | 0.01811 | 0.000448 | 0.02473 |
| Amazon-Music | 495/600 | 0.01620 | 0.000108 | 0.00665 |
| Epinions | 319/600 | 0.04958 | 0.001730 | 0.03489 |
| MovieLens-25M | 44/600 | 0.11281 | 0.011867 | 0.10520 |
| Method | S CPU | C CPU | T CPU/1000 | S wall | C wall | T wall/1000 | |
|---|---|---|---|---|---|---|---|
| 1 | ACRC (ours) | 68.005 | 11.264 | 0.182 | 68.018 | 11.264 | 0.182 |
| SCoRE/P | 476.288 | 7.163 | 25.615 | 476.457 | 7.165 | 25.625 | |
| SCoRE/U | 1653.562 | 8.617 | 30.457 | 1653.925 | 8.615 | 30.460 | |
| 8 | ACRC (ours) | 66.932 | 11.302 | 0.181 | 66.940 | 11.302 | 0.181 |
| SCoRE/P | 475.630 | 7.174 | 25.596 | 475.704 | 7.173 | 25.597 | |
| SCoRE/U | 1653.568 | 8.606 | 30.539 | 1653.935 | 8.605 | 30.553 |
| Method | LightGCN | XSimGCL | SIGformer | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Top20 | 0.2850 | 0.00000 | 0.00000 | 0.2876 | 0.00000 | 0.00000 | 0.1662 | 0.00000 | 0.00000 |
| PerK-PDCG | 0.2720 | 0.02626 | 0.07102 | 0.2703 | 0.04676 | 0.12140 | 0.1598 | 0.01043 | 0.02897 |
| UMC-top20 | 0.2402 | 0.12743 | 0.03786 | 0.1852 | 0.15663 | 0.04963 | 0.1774 | 0.08436 | 0.02729 |
| raw | 0.3249 | 0.01778 | 0.00607 | 0.3343 | 0.01671 | 0.00571 | 0.2447 | 0.01526 | 0.00551 |
| RB | 0.3275 | 0.01886 | 0.00644 | 0.3353 | 0.01705 | 0.00583 | 0.2458 | 0.01550 | 0.00560 |
| Comparator | LightGCN | XSimGCL | SIGformer |
|---|---|---|---|
| SCoRE/PerK UR | |||
| RB | |||
| SCoRE/UMC UR | |||
| Top20 | |||
| raw |
| Contrast | LightGCN | XSimGCL | SIGformer |
|---|---|---|---|
| Calibration with filter | |||
| Calibration without filter | |||
| Filter at new calibrator |
| Metric | Calibrator | LightGCN | XSimGCL | SIGformer |
|---|---|---|---|---|
| raw | ||||
| ACRC (ours) | ||||
| raw | ||||
| ACRC (ours) |
| Comparator | LightGCN | XSimGCL | SIGformer |
|---|---|---|---|
| Top20 | |||
| PerK-PDCG | |||
| UMC-20 | |||
| SCoRE / PerK U | |||
| SCoRE / PerK UR | |||
| SCoRE / UMC U |
| Method | NDCG | Recall | F1 | Length | |||
|---|---|---|---|---|---|---|---|
| Top20 | {\color[rgb]{0,0,1}0.2608}\pm 0.0010 | {\color[rgb]{0,0,1}0.7619}\pm 0.0007 | {\color[rgb]{0,0,1}0.8136}\pm 0.0002 | {\color[rgb]{0,0,1}0.6705} | {\color[rgb]{1,0,0}0.0000} | {\color[rgb]{1,0,0}0.0000} | |
| PerK-PDCG | |||||||
| UMC-20 | |||||||
| ACRC (ours) | {\color[rgb]{1,0,0}0.3244}\pm 0.0012 | {\color[rgb]{1,0,0}0.8030}\pm 0.0010 | {\color[rgb]{1,0,0}0.8388}\pm 0.0016 | {\color[rgb]{1,0,0}0.6911} | |||
| SCoRE / PerK UR | {\color[rgb]{0,0,1}0.0022} | ||||||
| SCoRE / UMC UR | {\color[rgb]{0,0,1}0.0017} |
Conformal Risk Control
Conformal risk control uses calibration data to choose prediction or action thresholds with finite-sample guarantees on expected error or other risks.
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