In this paper, we propose a sequential recommendation model that integrates Time-aware personalization, Multi-interest personalization, and Explanation personalization for Personalized Sequential Recommendation (TME-PSR). That is, we consider the differences across different users in temporal rhythm preference, multiple fine-grained latent interests, and the personalized semantic alignment between recommendations and explanations. Specifically, the proposed TME-PSR model employs a dual-view gated time encoder to capture personalized temporal rhythms, a lightweight multihead Linear Recurrent Unit architecture that enables fine-grained sub-interest modeling with improved efficiency, and a dynamic dual-branch mutual information weighting mechanism to achieve personalized alignment between recommendations and explanations. Extensive experiments on real-world datasets demonstrate that our method consistently improves recommendation accuracy and explanation quality, at a lower computational cost.
Figures & tables
Figure 1: Examples of movie interaction sequences of two different users, which show different preferences for time and interests. User 1 liked romance movies a long time ago, but recently the interest has shifted to superhero movies. User 2 has always liked superhero movies, but also follows both Marvel series and DC series two sub-interests.
Figure 2: Overall architecture of our TME-PSR. At the input layer, we propose a dual-view gated time encoder. Specifically, we use a time-aware encoder to extract short-term behavior patterns and long-term behavior patterns from input timestamps. Then, we adaptively weight the two patterns based on different user’s temporal rhythm preference, so as to extract personalized time-aware embeddings. At the encoding layer, we propose a multihead LRU architecture, each head captures a fine-grained sub-interest. At the prediction layer, we design a dynamic dual-branch MI weighting mechanism, so as to adaptively adjust the degree of semantic alignment between the recommendation branch and the explanation branch.
Model
AM-Electronics
AM-Movies
Yelp
Recommendation
Explanation
Recommendation
Explanation
Recommendation
Explanation
R@10
N@10
R@10
N@10
R@10
N@10
R@10
N@10
R@10
N@10
R@10
N@10
PITF
0.0286
0.0139
0.0880
0.0547
0.0235
0.0101
0.0984
0.0679
0.0204
0.0094
0.0333
0.0185
BPER
0.0307
0.0154
0.0901
0.0553
0.0281
0.0131
0.1028
0.0687
0.0212
0.0106
0.0393
0.0214
SCEMIM-GRU4Rec
0.0290
0.0152
0.0948
0.0629
0.0432
0.0216
0.1151
0.0771
0.0452
0.0228
0.0417
0.0233
SCEMIM-SASRec
0.0369
0.0195
0.1011
0.0681
0.0541
0.0257
0.1229
0.0809
0.0592
0.0364
0.0419
0.0231
Table 1: Recommendation and explanation performance, best results are marked in bold, second best results underlined. The improvement row is calculated as the percentage increase of the best result relative to the second best result.
Strategy
AM-Electronics
Rec
Exp
Time-aware
Multi-interest
Explanation
R@10
N@10
R@10
N@10
0.0327
0.0164
0.1087
0.0727
✓
0.0402
0.0197
0.1371
0.0912
✓
0.0361
0.0184
0.1312
0.0849
✓
0.0324
0.0160
0.1252
0.0844
Table 2: Ablation of key strategies the AM-Electronics dataset, best results are marked in bold, second best results underlined.
Figure 3: Comparison of four gating strategies. Results show that the model that adaptively focuses on both long-term and short-term features consistently achieves the best performance, which proves the effectiveness of the proposed method.
Figure 4: Left two columns show recommendation and explanation performance with different head numbers H under different embedding sizes d . Results show that the optimal head number increases with the increase of d . The third column shows the relationship between H and the encoder parameters. As H increases, the number of parameters decreases inversely.
Figure 5: Inference and training efficiency of GRU4Rec, SASRec, LRURec and the proposed multihead LRU. Results show that the proposed method outperforms the other three methods, and its efficiency increases with the head number H .
Figure 6: Visualization of multihead LRU output representation at d=120 , H=6 with t-SNE.
Figure 7: Comparison of three MI weighting strategies. Results show that the model with two dynamic weights consistently achieves the best performance, which proves the effectiveness of the proposed dynamic dual-branch MI weighting mechanism.
Figure 8: (a) Visualization of distributions of all interaction sequences average dynamic MI weights μˉrec and μˉexp . (b) K-means clustering based on (μ~rec,μ~exp) .
Appendix figures & tables6 assets
Supplementary material from the paper’s appendix.
Appendix
Dataset
Movies
Electronics
Yelp
# Users
22,248
18,129
90,742
# Items
15,458
10,435
46,372
# Explanations
31,451
23,541
119,874
# Actions
305,801
144,772
1,204,515
Avg. actions/users
13.75
7.95
13.27
Avg. actions/items
19.78
13.87
25.98
Appendix
Table 3: The statistics of the preprocessed datasets.
Model
AM-Electronics
AM-Movies
Yelp
Recommendation
Recommendation
Recommendation
R@10
N@10
R@10
N@10
R@10
N@10
GRU4Rec
0.0259
0.0134
0.0431
0.0208
0.0451
0.0228
SASRec
0.0342
0.0182
0.0536
0.0256
0.0604
0.0364
FMLPRec
0.0357
0.0186
0.0558
0.0253
0.0620
0.0403
LRURec
0.0345
0.0159
0 .0560
0.0259
0.0625
0.0397
Appendix
Table 4: overall with non-SCEMIM models
Strategy
AM-Electronics
AM-Movies
Yelp
Rec
Exp
Rec
Exp
Rec
Exp
Time-aware
Multi-interest
Explanation
R@10
N@10
R@10
N@10
R@10
N@10
R@10
N@10
R@10
N@10
R@10
N@10
0.0327
0.0164
0.1087
0.0727
0.0549
0.0269
0.1171
0.0830
0.0650
0.0397
0.0422
0.0230
✓
0.0402
0.0197
0.1371
0.0912
0.0563
0.0266
0.1287
0.0841
0.0672
0.0410
0.0454
0.0250
✓
0.0361
0.0184
0.1312
0.0849
0.0550
0.0274
0.1300
0.0897
0.0652
0.0399
0.0428
0.0234
✓
0.0324
0.0160
0.1252
0.0844
0.0567
0.0272
0.1242
0.0868
0.0654
0.0399
0.0437
0.0238
Appendix
Table 5: Ablation of key strategies on three datasets, best results are marked in bold, second best results underlined.
Figure 9: Impact of hyperparameters across three datasets. Results show that when set α=0.9 and set β=0.1 , the proposed model achieve the best performance.
Figure 10: Relationship between the gating parameters γrec and the average time interval tˉ (left) and relationship between the gating parameters γexp and tˉ (right). Each point represents a single user sequence. Results show that as tˉ increases, the two gating parameters decrease linearly.
Figure 11: Examples of three representative user types, correspond to the three clusters in Figure 7(b).