Source-linked AI summary

Towards Controllable and Personalized Review Generation

Pan Li, Alexander Tuzhilin

arXiv:1910.03506v2cs.CLcs.LGstat.ML

TL;DR

Review generation must account for product context, sentiment, review structure, and a specific user’s style. RevGAN combines hierarchical text encoding, sentiment-conditioned discrimination, and personalized decoding; its authors report better generation performance and reviews resembling organic ones.

  • Problem

    Prior review generators did not consistently combine hierarchical review structure with product context and controllable personalization for specific products and users.

    Source: §1 · p. 1
  • Method

    RevGAN uses a self-attentive recursive autoencoder, conditional discriminator, and personalized decoder to generate reviews from product descriptions, sentiment labels, and users’ history.

    Source: §1 · p. 1, §3 · p. 3
  • Results

    RevGAN significantly and consistently outperforms state-of-the-art baselines across multiple real-world datasets, and its reviews resemble organic reviews.

    Source: §1 · p. 1
  • Takeaways & Limitations

    Generated reviews are reported to resemble organic reviews and follow the same statistical linguistic laws.

    Source: §1 · p. 2

Abstract

from arXiv · show

In this paper, we propose a novel model RevGAN that automatically generates controllable and personalized user reviews based on the arbitrarily given sentimental and stylistic information. RevGAN utilizes the combination of three novel components, including self-attentive recursive autoencoders, conditional discriminators, and personalized decoders. We test its performance on the several real-world datasets, where our model significantly outperforms state-of-the-art generation models in terms of sentence quality, coherence, personalization and human evaluations. We also empirically show that the generated reviews could not be easily distinguished from the organically produced reviews and that they follow the same statistical linguistics laws.

1 Introduction

RevGAN targets review generation that is controllable and personalized to a product and user, addressing gaps in prior models’ handling of review structure, context, and writing style. The authors report stronger generation performance and reviews resembling organic ones.

1 Introduction

  • Online marketplaces need tools to encourage review feedback because only a small fraction of users take time to write reviews.Automatic generation uses product information and user behavior to produce reviews with designated sentiment and personalized style.Source: §1 · p. 1
  • Prior models either neglected hierarchical review structure, limiting length and coherence, or lacked controllable personalization for specific products and users.The authors also identify omission of product descriptions as a source of reduced credibility and diversity.Source: §1 · p. 1
  • RevGAN generates reviews from product descriptions, sentiment labels, and users’ historical reviews through a three-stage process.The stages map text into embeddings, condition generation on sentiment, and decode using users’ history-derived writing styles.Source: §1 · p. 1
  • RevGAN significantly and consistently outperforms state-of-the-art baselines, while its reviews resemble organic reviews and follow the same statistical linguistic laws.The reported results span multiple real-world datasets.Source: §1 · pp. 1–2
  • RevGAN combines a self-attentive recursive autoencoder, conditional discriminator, and personalized decoder to capture review structure and semantics, control sentiment, and incorporate users’ vocabulary preferences.The authors report that human evaluation validates the personalized decoder’s contribution to generated-review personalization and credibility.Source: §1 · p. 2

2 Related Work

The related work reviews automated product-review generation and GAN approaches for natural language generation, highlighting shortcomings that RevGAN addresses.

2 Related Work

  • The section frames automated review generation and GAN for NLG as the two strands of related work leading to RevGAN.Source: §2 · p. 2

2.1 Automated Review Generation

  • Prior review generators used Seq2Seq variants, while hierarchical models addressed review structure; the authors identify missing product information, writing style, and coherence as remaining limitations.Examples include RNN (Yao et al., 2017), Aspect-Sentiment Score, and a hierarchical autoencoder (Li et al., 2015).Source: §2.1 · p. 2

2.2 GAN for NLG

  • GAN-based text generators face high computational complexity on long texts, and conditional GAN label concatenation may not sufficiently steer high-dimensional latent embeddings.RevGAN conditions sentiment on the discriminator; the authors report outperforming other GAN-based NLG models and Conditional GAN in sentiment accuracy.Source: §2.2 · pp. 2–3

3 Models

RevGAN combines a self-attentive recursive autoencoder, a conditional discriminator, and a personalized decoder to generate reviews. Its components encode reviews and descriptions, condition generation on sentiment, and incorporate user writing styles.

3.1 Self-Attentive Recursive AutoEncoder

  • Bidirectional GRUs and self-attention produce sentence embeddings, which are recursively merged by concatenation in a binary tree into review embeddings trained through reconstruction.The root node represents the full review; the decoder unfolds it to reconstruct the review.Source: §3.1 · pp. 3–4

3.2 Conditional Discriminator

  • The conditional discriminator uses sentiment labels to judge matched original reviews as positive and generated or opposite-sentiment reviews as negative examples.The authors describe this conditioning as a way to make generation controllable.Source: §3.2 · p. 4

3.3 Personalized Decoder

  • The personalized decoder represents a user’s writing style with historical word frequencies and combines that vector with the word distribution when sampling generated words.For users without historical reviews, the authors set the style vector to the identity matrix; they report improved generation results and helpfulness from personalization.Source: §3.3 · pp. 4–5

4 Experimental Results

The experiments use three Amazon review subsets and specify implementation settings for the autoencoder and GAN models.

4.1 Dataset

  • The evaluation uses 44,006 reviews from 3,697 users across 6,039 items in Amazon’s Musical Instrument, Automotive, and Patio subsets.Source: §4.1 · p. 5

4.2 Experiment Settings

  • The autoencoder uses bidirectional GRUs with 300-dimensional embeddings, batch size 128, gradient clipping at norm 1, and beam size 3.Its learning rate starts at 1e-3 and halves every 50 epochs until convergence.Source: §4.2 · p. 5
  • GAN baselines use the Texygen toolkit; RevGAN’s generator and conditional discriminator are MLPs with 300 hidden layers and learning rates of 5e-5 and 1e-5, respectively.The generator updates five times per epoch and the discriminator once; training runs for 30,000 updates and takes about 12 hours on a Tesla K80.Source: §4.2 · p. 5

4.3 Evaluation Metrics

RevGAN significantly and consistently outperforms the selected benchmark models. The evaluation also measures generation quality, coherence, sentiment control, and whether people can distinguish generated reviews from original ones.

4.3 Evaluation Metrics

  • Evaluation uses log-likelihood, perplexity, Word Mover Distance, BLEU, ROUGE, and sentiment accuracy, defined as the share of reviews matching the given sentiment label.Source: §4.3 · p. 5
  • In human evaluation, participants classify randomly selected original and generated reviews, and the reported significance test finds RevGAN reviews indistinguishable from original data.Source: §4.3 · p. 5

4.4 Baseline Models

  • RevGAN significantly and consistently outperforms the selected benchmark models, including MLE, SeqGAN, LeakGAN, RankGAN, and Attr2Seq.Source: §4.4 · pp. 5–6

4.5 Significance Testing

The authors use paired significance tests for metric comparisons and a chi-square test to assess whether human assessments are associated with whether reviews are generated or original.

4.5 Significance Testing

  • For metric comparisons, bootstrap resampling estimates asymptotic standard errors, followed by paired two-sample t-tests of population means.Source: §4.5 · p. 6
  • The chi-square test finds no significant association between human assessment and actual review status, supporting the authors’ claim that generated reviews are indistinguishable from original ones.Source: §4.5 · p. 6
  • The human-assessment analysis tests independence between participants’ judgments and whether each review is actually generated or original.Source: §4.5 · p. 6

4.6 Evaluation of review generation

RevGAN significantly outperforms baseline text-generation models on sentence quality and coherence across three Amazon product domains. The combination of all three RevGAN components gives the best generation performance.

4.6 Evaluation of review generation

  • On average, RevGAN reports a 5% increase in Word Mover Distance (WMD), 80% improvement in BLEU, and 10% rise in ROUGE over baseline text-generation models.The comparison covers musical instruments, automotive, and patio products; bootstrap hypothesis tests confirm significant improvement.Source: §4.6 · p. 6
  • The combination of all three RevGAN components gives the best generation performance among the tested model variations.Source: §4.6 · p. 6
  • Bootstrap hypothesis tests confirm significant improvement, supporting the authors’ claim of state-of-the-art review-generation results.The reported comparison spans three Amazon product domains.Source: §4.6 · p. 6

4.7 Evaluation of controllable generation

The evaluation tests whether RevGAN can control generated-review sentiment through contextual labels. With positive and negative labels preset, RevGAN beats Attr2Seq and Conditional GAN on sentiment accuracy.

4.7 Evaluation of controllable generation

  • RevGAN’s controllable-generation evaluation measures sentiment accuracy after fixing the contextual sentiment label as positive or negative.Source: §4.7 · p. 6
  • The comparison conditions Attr2Seq and Conditional GAN on the same positive and negative sentiment labels.Source: §4.7 · p. 6
  • Under these conditions, RevGAN beats the state-of-the-art algorithm Attr2Seq and Conditional GAN on sentiment accuracy.Source: §4.7 · p. 6

4.8 Evaluation of Personalized Generation

The empirical study compares generated and consumer-written reviews for machine detection and helpfulness, and compares personalized with non-personalized outputs. Personalized reviews receive higher helpfulness scores than non-personalized outputs, while generated and consumer-written reviews show no statistical difference in helpfulness.

4.8 Evaluation of Personalized Generation

  • At the 95% confidence level, the study reports no statistical difference between machine-generated and human-written reviews.The study sent 100 questionnaires and received 36 responses; Table 3 reports the confusion matrix.Source: §4.8 · p. 6, Table 3 · p. 7
  • Generated and consumer-written reviews show no statistical difference in helpfulness, with average scores of 3.10 and 3.03, respectively.Source: §4.8 · pp. 6–7
  • Personalized generated reviews score 3.10 for helpfulness versus 2.91 for non-personalized generated reviews, a significant improvement attributed to users’ writing style.Source: §4.8 · p. 7

4.9 Showcase

The showcase presents generated reviews across contextual labels and domains, and examines how personalization changes their wording. Personalized outputs tend to use more words from the user’s history corpus.

4.9 Showcase

  • Personalized generated reviews tend to use more words from the user’s history corpus than the modification process’s comparison outputs.Source: §4.9 · p. 7
  • Both original and generated reviews satisfy Heap’s Law and Zipf’s Law in the reported linguistic checks.Figure 3 is identified as the Heap’s Law verification and Figure 4 as the Zipf’s Law verification.Source: §4.9 · p. 7, Figure 3 · p. 7, Figure 4 · p. 7

5 Conclusion

RevGAN generates personalized product reviews from product embeddings rather than labels, targeting specific products and users. The authors report better performance than baseline models and reviews similar to organic user reviews, while identifying further directions for the task.

5 Conclusion

  • RevGAN generates personalized product reviews from product embeddings rather than labels, targeting specific products and users.The conclusion names self-attentive recursive autoencoders, conditional discriminators, and personalized decoders as components of the approach.Source: §5 · p. 7
  • RevGAN performs significantly better than baseline models, and its generated reviews are very similar to organically generated user reviews.The conclusion points to Section 5.2 and Table 3 for this comparison.Source: §5 · p. 8
  • Future work includes accepting user-provided keywords and developing methods to distinguish the review types discussed in the paper from organic reviews.Source: §5 · p. 8
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