Organizations: School of Computer Science and Engineering, University of New South Wales, Sydney, Australia · State Key Laboratory of Cognitive Intelligence, School of Computer Science and Technology, University of Science and Technology of China, Hefei, China · The Hong Kong University of Science and Technology (Guangzhou)
Post-hoc residual correction can reduce forecasting error, but always-on updates often fail to generalize: when residual signals are weak or noisy, expressive correctors can overfit and even increase the overall forecasting errors. We introduce CRC, a robust residual correction framework that couples a hybrid corrector with a validation-calibrated selective deployment rule. CRC proposes corrections via a conservative ridge "floor" plus conditional nonlinear refinement, but deploys them only when held-out evidence indicates net error reduction over a frozen baseline forecaster. CRC treats when to revise a forecast as a validation-calibrated deployment decision, not only how to fit residuals. Across standard long-sequence benchmarks and multiple backbones, CRC improves horizon-averaged MSE and MAE in most dataset-backbone pairs, with particularly large gains on complex datasets (e.g., over 20% relative MSE reduction on Traffic). We additionally report the non-degradation rate (NDR) as a stability diagnostic of harmful updates and ablate the validation-calibrated "firewall" that stabilizes MSE gains.
Figures & tables
Figure 1: Overview of the CRC framework. CRC first extracts structured residual representations, then proposes conservative and conditional correction components, and finally applies a validation-calibrated deployment rule that deploys corrections only when held-out evidence supports them.
Dataset
Model
MSE (Baseline)
MSE (CRC)
Imp MSE (%)
MAE (Baseline)
MAE (CRC)
Imp MAE (%)
ETTh1
DLinear
0.4603
0.4582
0.46
0.4568
0.4554
0.29
PatchTST
0.4478
0.4468
0.22
0.4476
0.4454
0.50
TimeXer
0.4441
0.439
1.14
0.4451
0.444
0.24
TimesNet
0.4565
0.4562
0.06
0.4528
0.4525
0.06
ETTh2
DLinear
0.5641
0.5383
4.57
0.5194
0.497
4.32
PatchTST
0.3807
0.3794
0.35
0.4092
0.4078
0.36
Table 1: Horizon-averaged MSE and MAE improvements of CRC across datasets and backbones (averaged over horizons 96, 192, 336, 720). Improvements are relative to the baseline and positive values indicate gains. Full horizon-wise results are reported in Appendix Table 7 .
Config
B1 MAE
B1 MSE
B1 NDR
B2 MAE
B2 MSE
B2 NDR
B3 MAE
B3 MSE
B3 NDR
G0 Baseline
0.4108
0.3962
—
0.4654
0.4874
—
0.2184
0.1685
—
G1 Always-on
0.4738
0.4665
8.2
0.5689
0.6328
10.6
0.2326
0.1803
33.9
G2 Ridge+val gate
0.4097
0.3941
97.9
0.4693
0.4920
97.1
0.2111
0.1626
90.0
G3 No dir gate
0.4079
0.3865
81.8
0.4684
0.4786
78.5
0.2098
0.1611
81.5
G4 Deploy-only
0.4097
0.3941
62.1
0.4592
0.4838
77.8
0.2081
0.1584
79.4
G5 Full CRC
0.3914
0.3780
80.3
0.4392
0.4612
79.7
0.1903
0.1408
78.5
Table 3: Controlled deployment ladder (G0–G5) on B1–B3 (seed 2021). B1/B2/B3: ETTh1+DLinear at pred_len 96/336 and Weather+TimesNet at 96. Not horizon-averaged like Table 1 . G0 baseline, G1 always-deploy (blend search off; τ /direction gate retained), G2 ridge+validation gate only (no MLP), G3 w/o direction gate, G4 deploy-only encoder, G5 full CRC. Lower MAE/MSE and higher NDR (%) are better.
Dataset
TimeXer
TimesNet
PatchTST
DLinear
Winner
ETTh1
−0.0223
0.0000
−0.0036
−0.0217
pir
ETTh2
−0.0076
0.0053
0.0141
−0.1673
crc
ETTm1
0.0116
0.0116
0.0042
−0.0065
crc
ETTm2
0.0205
0.0138
0.0102
−0.0537
crc
Weather
0.0117
0.0192
0.0371
0.0267
crc
Electricity
0.0066
−0.0001
0.0123
0.0154
crc
Table 4: Horizon-averaged relative forecasting error differences between PIR and CRC ( Δ=PIR−CRC ; positive indicates CRC better). Winner summarizes the majority sign of Δ across backbone–horizon pairs for each dataset. Full horizon-wise results (including MAE) are reported in Appendix Table 8 .
Figure 2: NDR stability curves. Non-degradation rate (NDR, %) of PIR vs. CRC across horizons on Weather and ETTm2 (higher is better). Each panel corresponds to one backbone; annotations report mean Δ NDR in percentage points (pp). Exact values are provided in Appendix Table 5 .
School of Science for Open and Environmental Systems, Graduate School of Science and Technology, Keio University, Japan · Department of System Design, Faculty of Science and Technology, Keio University, Japan
School of Science for Open and Environmental Systems, Graduate School of Science and Technology, Keio University, Yokohama 223-8522, Japan · Department of System Design, Faculty of Science and Technology, Keio University, Yokohama 223-8522, Japan