OPRIDE: Offline Preference-based Reinforcement Learning via In-Dataset Exploration
Authors: Yiqin Yang, Hao Hu, Yihuan Mao, Jin Zhang, Chengjie Wu, Yuhua Jiang, Xu Yang, Runpeng Xie, Yi Fan, Bo Liu, Yang Gao, Bo Xu, Chongjie Zhang
Organizations: The Key Laboratory of Cognition and Decision Intelligence for Complex Systems, Institute of Automation, Chinese Academy of Sciences · Moonshot AI · Tsinghua University · Amazon · University of Arizona · Washington University in St. Louis
Preference-based reinforcement learning (PbRL) can help avoid sophisticated reward designs and align better with human intentions, showing great promise in various real-world applications. However, obtaining human feedback for preferences can be expensive and time-consuming, which forms a strong barrier for PbRL. In this work, we address the problem of low query efficiency in offline PbRL, pinpointing two primary reasons: inefficient exploration and overoptimization of learned reward functions. In response to these challenges, we propose a novel algorithm, Offline PbRL via In-Dataset Exploration (OPRIDE), designed to enhance the query efficiency of offline PbRL. OPRIDE consists of two key features: a principled exploration strategy that maximizes the informativeness of the queries and a discount scheduling mechanism aimed at mitigating overoptimization of the learned reward functions. Through empirical evaluations, we demonstrate that OPRIDE significantly outperforms prior methods, achieving strong performance with notably fewer queries. Moreover, we provide theoretical guarantees of the algorithm's efficiency. Experimental results across various locomotion, manipulation, and navigation tasks underscore the efficacy and versatility of our approach.
Figures & tables
Figure 1: The procedure of OPRIDE consists of two phases. In the first offline phase, we select query based on exploration mechanism. The blue circles ∙ and red triangles ▲ represent the value estimation Vψ1 and Vψ2 , respectively. In the second stage, we first learn an reward function based on the preference dataset and then annotate the reward-free dataset. Next, we adjust the discount factor to reduce the impact of noise in the reward learning.
Dpref←Dpref∪{(τk,1,τk,2,ok)}.
Algorithm 1 Offline Preference-Based Reinforcement Learning with In-Dataset Exploration
Domain
Task
OPRL
PT
PT+PDS
IDRL
OPRIDE
Metaworld
lever-pull
63.2 ± 10.4
49.2 ± 3.7
51.7 ± 0.1
33.1 ± 1.2
51.8 ± 1.6
peg-insert-side
3.5 ± 1.8
16.8 ± 0.1
12.4 ± 1.4
67.4 ± 0.1
79.0 ± 0.2
plate-slide
77.4 ± 1.6
4.9 ± 0.0
37.3 ± 2.3
79.6 ± 3.5
79.9 ± 4.6
push
10.6 ± 1.5
16.7 ± 5.0
1.8 ± 0.4
30.7 ± 5.3
59.1 ± 5.4
push-back
0.8 ± 0.0
1.1 ± 0.4
1.1 ± 0.1
14.0 ± 1.1
17.7 ± 2.0
push-wall
7.4 ± 4.2
74.8 ± 14.4
3.4 ± 0.9
89.2 ± 3.2
102.2 ± 1.2
Table 1: Performance of offline RL algorithm on the reward-labeled dataset with different preference reward learning methods on the Meta-World tasks over five random seeds.
Domain
Task
OPRL
PT
PT+PDS
IDRL
OPRIDE
Antmaze
umaze
76.3 ± 3.7
77.5 ± 4.5
84.5 ± 8.5
85.5 ± 3.4
87.5 ± 5.6
umaze-diverse
72.5 ± 3.4
68.0 ± 3.0
78.0 ± 6.0
69.1 ± 4.2
73.1 ± 2.4
medium-play
0.0 ± 0.0
63.5 ± 0.5
72.5 ± 6.5
63.8 ± 4.1
62.2 ± 2.0
medium-diverse
0.0 ± 0.0
63.5 ± 4.5
58.0 ± 4.0
65.7 ± 4.1
69.4 ± 5.2
large-play
7.3 ± 0.9
6.5 ± 2.5
9.0 ± 8.0
18.7 ± 3.4
27.5 ± 12.5
large-diverse
6.9 ± 2.4
23.5 ± 0.5
8.5 ± 2.5
14.3 ± 2.5
21.5 ± 1.5
Table 2: Performance of offline RL algorithm on the reward-labeled dataset with different preference reward learning methods on the Antmaze tasks over five random seeds.
Task
PT
PDS + Random Query
VDS + Random Query
VDS + Disagreement
OPRIDE (VDS+IDE)
bin-picking
31.9 ± 16.2
53.4 ± 19.0
71.9 ± 9.0
78.5 ± 17.8
93.3 ± 3.2
button-press-wall
58.8 ± 0.9
59.4 ± 0.9
77.2 ± 0.8
67.4 ± 5.4
77.7 ± 0.1
door-close
65.1 ± 10.1
62.4 ± 8.7
72.3 ± 0.1
88.3 ± 0.7
94.8 ± 1.1
faucet-close
57.8 ± 0.9
46.2 ± 0.2
59.4 ± 8.5
48.7 ± 0.6
73.1 ± 0.8
peg-insert-side
16.8 ± 0.1
12.4 ± 1.4
13.8 ± 4.4
9.7 ± 8.5
79.0 ± 0.2
reach
82.0 ± 0.8
84.3 ± 0.9
83.3 ± 0.1
86.6 ± 0.1
88.0 ± 0.5
Table 3: Ablation of the query selection module on the Meta-World tasks. We report the performance of offline RL algorithm on the reward-labeled dataset with various query selection and policy extration mechanism. IDE and VDS represent the In-Dataset Exploration module and the Variance-based Discount Scheduling module proposed in Section 3.1 , respectively.
Domain
Tasks
Zero
Random
Negative
OPRIDE
Metaworld
coffee-push
7.6 ± 4.3
5.8 ± 2.7
0.7 ± 0.1
59.4 ± 24.8
disassemble
9.3 ± 0.4
16.8 ± 7.3
10.1 ± 0.2
26.6 ± 4.9
hammer
38.1 ± 6.4
46.1 ± 2.4
22.6 ± 1.8
50.3 ± 3.2
push
57.5 ± 1.5
34.4 ± 17.3
4.6 ± 2.3
59.1 ± 5.4
push-wall
81.9 ± 3.8
80.1 ± 0.9
17.6 ± 1.9
102.2 ± 1.2
soccer
33.3 ± 1.6
41.1 ± 8.8
44.0 ± 6.4
45.4 ± 3.9
Table 4: Comparison between the survival instinct and OPRIDE.
Figure 2: Performance of offline preference-based RL algorithms with various queries. OPRIDE achieves a better query efficiency across tasks and number of queries.
Appendix figures & tables15 assets
Supplementary material from the paper’s appendix.
Appendix
Dpref←Dpref∪{(τk1,τk2,ok)}.
Appendix
Algorithm 2 Theoretical Analysis Version of OPRIDE
Table 5: Performance of offline RL algorithm on the reward-labeled dataset with different preference reward learning methods on the Meta-World tasks.
Domain
Tasks
OPRL
PT
PT+PDS
OPRIDE
Mujoco
hopper-medium
23.0 ± 0.1
36.9 ± 2.1
35.8 ± 1.8
38.5 ± 2.2
hopper-medium-expert
57.7 ± 23.7
68.0 ± 2.6
69.1 ± 1.7
92.3 ± 15.8
walker2d-medium
70.6 ± 1.1
71.7 ± 2.6
70.9 ± 1.8
72.7 ± 1.8
walker2d-medium-expert
108.3 ± 3.8
109.4 ± 0.3
108.4 ± 0.5
110.3 ± 0.2
halfcheetah-medium
41.9 ± 0.1
42.1 ± 0.1
41.5 ± 0.1
42.4 ± 0.1
halfcheetah-medium-expert
81.8 ± 0.6
81.9 ± 0.1
82.4 ± 0.2
86.5 ± 1.5
Appendix
Table 6: Performance of offline RL algorithm on the reward-labeled dataset with different preference reward learning methods on the Mujoco tasks.
γsmall
0.5
0.6
0.7
0.8
0.9
0.95
bin-picking
72.1 ± 23.9
87.8 ± 2.7
93.3 ± 3.2
84.6 ± 9.4
74.8 ± 33.5
70.9 ± 9.4
button-press-wall
77.6 ± 0.3
77.4 ± 0.3
77.7 ± 0.1
71.0 ± 0.7
69.2 ± 0.9
68.1 ± 9.7
door-close
88.4 ± 0.8
89.9 ± 0.7
94.8 ± 1.1
90.0 ± 2.1
91.1 ± 1.5
87.6 ± 0.7
faucet-close
58.1 ± 5.2
58.2 ± 12.5
73.1 ± 0.8
61.4 ± 2.7
55.1 ± 3.7
57.4 ± 12.1
Appendix
Table 7: Performance of offline RL algorithm on the reward-labeled dataset with various discount factor values γsmall on the high variance data points.
Domain
Tasks
OPRIDE (Reward Difference)
OPRIDE (Value Function Difference)
Metaworld
bin-picking
78.5 ± 17.8
93.3 ± 3.2
button-press-wall
67.4 ± 5.4
77.7 ± 0.1
door-close
88.3 ± 0.7
94.8 ± 1.1
faucet-close
48.7 ± 0.6
73.1 ± 0.8
peg-insert-side
9.7 ± 8.5
79.0 ± 0.2
reach
86.6 ± 0.1
88.0 ± 0.5
Appendix
Table 8: Ablation study on the metaworld tasks.
Domain
Tasks
OPRIDE (Penalise Reward)
OPRIDE (Penalise Discount Factor)
Metaworld
bin-picking
53.4 ± 19.0
93.3 ± 3.2
button-press-wall
59.4 ± 0.9
77.7 ± 0.1
door-close
62.4 ± 8.7
94.8 ± 1.1
faucet-close
46.2 ± 0.2
73.1 ± 0.8
peg-insert-side
12.4 ± 1.4
79.0 ± 0.2
reach
84.3 ± 0.9
88.0 ± 0.5
Appendix
Table 9: Ablation studies about penalizing rewards and the discount factor.
m%
10%
20%
30%
40%
50%
bin-picking
71.4 ± 3.3
85.9 ± 3.9
93.3 ± 3.2
88.7 ± 2.6
73.2 ± 2.7
button-press-wall
67.2 ± 2.1
70.2 ± 0.6
77.7 ± 0.1
77.5 ± 0.3
77.5 ± 0.6
door-close
87.9 ± 1.2
89.6 ± 1.0
94.8 ± 1.1
89.6 ± 0.8
87.3 ± 0.9
faucet-close
56.8 ± 2.6
62.3 ± 1.6
73.1 ± 0.8
58.7 ± 1.9
57.6 ± 2.1
Appendix
Table 10: Ablation study for the hyperparameter m from 10% to 50%.
Tasks
Continuous annealing
Threshold-based
bin-picking
94.1 ± 3.7
93.3 ± 3.2
button-press-wall
77.4 ± 0.3
77.7 ± 0.1
door-close
94.3 ± 1.7
94.8 ± 1.1
faucet-close
71.6 ± 0.9
73.1 ± 0.8
peg-insert-side
80.5 ± 0.3
79.0 ± 0.2
reach
87.5 ± 0.6
88.0 ± 0.5
Appendix
Table 11: Ablation study for the discount factor mechanism on the Meta-World tasks.
M
2
5
10
bin-picking
1.1h
1.2h
1.3h
button-press-wall
1.1h
1.1h
1.2h
door-close
1.1h
1.2h
1.3h
faucet-close
0.9h
1.0h
1.2h
peg-insert-side
1.0h
1.1h
1.3h
Appendix
Table 12: Computational Cost for OPRIDE with ensemble M , where h is the hour. The report time is the sum of the reward function training time and the policy training time.
Query Number
1 (BC)
10 (0.1%)
13
20 (0.2%)
30 (0.3%)
50 (0.5%)
100 (1.0%)
Hammer-v2
13.2 ± 3.3
50.3 ± 3.2
55.4 ± 2.6
75.9 ± 2.2
79.1 ± 2.6
79.5 ± 2.7
79.9 ± 2.3
Coffee-push-v2
2.5 ± 1.1
56.7 ± 2.8
57.6 ± 2.5
55.3 ± 3.1
58.9 ± 3.7
59.4 ± 3.5
59.5 ± 3.4
Disassemble-v2
9.3 ± 1.7
26.6 ± 2.8
27.8 ± 3.1
30.6 ± 5.2
35.7 ± 4.8
37.2 ± 4.6
38.3 ± 5.1
Push-v2
1.2 ± 0.6
50.9 ± 1.8
63.7 ± 2.1
76.8 ± 2.4
82.7 ± 2.6
83.6 ± 2.3
84.0 ± 2.2
Appendix
Table 13: Performance of OPRIDE with various query numbers.
Tasks
PT
IPL
CPL
LiRE
OPRIDE
lever-pull
49.2 ± 3.7
50.2 ± 2.1
50.1 ± 2.5
51.2 ± 1.8
51.8 ± 1.6
peg-insert-side
16.8 ± 0.1
53.8 ± 0.4
54.7 ± 0.3
63.1 ± 0.2
79.0 ± 0.2
plate-slide
4.9 ± 0.0
60.9 ± 5.6
61.7 ± 4.8
68.3 ± 4.3
79.9 ± 4.6
push
16.7 ± 5.0
38.5 ± 4.2
39.2 ± 3.9
45.5 ± 3.7
59.1 ± 5.4
push-back
1.1 ± 0.4
9.8 ± 1.6
9.3 ± 1.8
13.2 ± 1.5
17.7 ± 2.0
push-wall
74.8 ± 14.4
85.8 ± 4.7
87.3 ± 3.8
90.2 ± 3.6
102.2 ± 1.2
Appendix
Table 14: Comparison with one-stage framework and sequential ranked list method.
Tasks
OPRL
PT
PT+PDS
IDRL
OPRIDE
Pong
9.6 ± 1.4
9.4 ± 1.0
8.5 ± 1.8
15.3 ± 1.1
17.8 ± 1.3
Breakout
125.9 ± 14.2
79.9 ± 13.9
86.3 ± 13.8
153.7 ± 14.5
256.7 ± 14.3
Q*bert
7924.6 ± 376.1
7482.9 ± 353.4
6844.2 ± 394.6
8294.1 ± 359.7
13535.2 ± 327.2
Seaquest
2784.1 ± 72.7
2538.3 ± 78.9
2459.6 ± 74.5
2941.2 ± 69.2
3478.4 ± 71.3
Asterix
164.9 ± 21.5
155.8 ± 24.6
146.3 ± 27.4
357.4 ± 30.1
426.9 ± 28.7
Appendix
Table 15: Experiments on pixel-based Atari tasks with human-in-the-loop.
Preference-based reinforcement learning learns policies from comparisons or rankings of behaviors instead of requiring hand-designed numerical rewards.
University of Southern California, Los Angeles, CA, USA. · Beijing University of Chemical Technology, Beijing, China. · George Mason University, Fairfax, VA, USA. +1