=Paper= {{Paper |id=Vol-3740/paper-247 |storemode=property |title=DeBERTa-v3 with R-Drop regularization for Multi-Author Writing Style Analysis |pdfUrl=https://ceur-ws.org/Vol-3740/paper-247.pdf |volume=Vol-3740 |authors=Zhijian Huang,Leilei Kong |dblpUrl=https://dblp.org/rec/conf/clef/HuangK24c }} ==DeBERTa-v3 with R-Drop regularization for Multi-Author Writing Style Analysis== https://ceur-ws.org/Vol-3740/paper-247.pdf
                         DeBERTa-v3 with R-Drop regularization for Multi-Author
                         Writing Style Analysis
                         Notebook for the PAN Lab at CLEF 2024

                         Zhijian Huang1 , Leilei Kong1,†
                         1
                             Foshan University, Foshan, Guangdong, China


                                        Abstract
                                        The Multi-Author Writing Style Analysis task aims to identify points within a multi-author document where the
                                        author changes, using variations in writing style as indicators. Existing approaches face challenges in achieving
                                        high robustness due to the complexity of distinguishing between different authors’ styles. To address these
                                        challenges, we use a model based on base version of the DeBERTa-v3 model combined with R-Drop regularization.
                                        We trained the DeBERTa-v3 model independently on three different datasets representing varying difficulty
                                        levels, using R-Drop during training to enhance the model’s performance by reducing uncertainty and improving
                                        generalization. In experiments, our method achieves F1 scores of 0.985, 0.815, and 0.826 on Task 1, Task 2, and
                                        Task 3 of the official test set for the PAN 2024 Multi-Author Writing Style Analysis, respectively.

                                        Keywords
                                        Multi-Author Writing Style Analysis, DeBERTa-v3, R-Drop




                         1. Introduction
                              Multi-Author Writing Style Analysis aims to identify points within a multi-author document where
                         authorship changes occur. This task is based on the hypothesis that variations in writing style can serve
                         as indicators of changes in authorship. PAN’s evaluation focuses on distinguishing authorship changes
                         at the paragraph level under varying conditions of topical similarity [1, 2].
                              Various methods have been proposed to tackle this task, ranging from traditional machine learning
                         algorithms to advanced deep learning models. Earlier approaches predominantly relied on features
                         extracted from the text, such as lexical and syntactic markers, to differentiate between authors. However,
                         these methods often fall short in scenarios where stylistic differences are minute. More recent approaches
                         employ pre-trained language models [3] like BERT [4] and its variants, which have shown promise in
                         capturing deeper contextual information.
                              To further enhance the robustness of pre-trained language model approaches, we use the advanced
                         pre-trained language model DeBERTa(Decoding-enhanced BERT with Disentangled Attention)-v3 [5]
                         and combine it with the R-Drop regularization [6]. The DeBERTa-v3 model, known for its ability to
                         capture complex language structures and patterns through its decoding-enhanced attention mechanism,
                         serves as the foundation. By incorporating R-Drop, which introduces dual regularization during training,
                         we enhance the model’s performance by reducing uncertainty and improving generalization, thereby
                         effectively mitigating overfitting and maintaining model stability.


                         2. Related work
                             Pre-trained language models have revolutionized the field of natural language processing (NLP),
                         demonstrating significant improvements across various tasks, including multi-author writing style
                         analysis. Models such as BERT [4], RoBERTa [7] and DeBERTa [5] have set new benchmarks by

                          CLEF 2024: Conference and Labs of the Evaluation Forum, September 09–12, 2024, Grenoble, France
                         †
                           corresponding author
                          $ huangzhijian1024@163.com (Z. Huang); kongleilei@fosu.edu.cn (L. Kong)
                           0009-0002-5049-2093 (Z. Huang); 0000-0002-4636-3507 (L. Kong)
                                     © 2024 Copyright for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).


CEUR
                  ceur-ws.org
Workshop      ISSN 1613-0073
Proceedings
leveraging large-scale unsupervised pre-training followed by fine-tuning on specific tasks. These
models capture contextual information bidirectionally, making them highly effective for tasks requiring
nuanced understanding of both writing styles and semantic content.
      In multi-author writing style analysis, pre-trained language models are utilized to encode textual
features that are indicative of different authors’ styles. For instance, Chen et al. [8] demonstrated the
use of a pre-trained language model for generating sentence embeddings optimized through contrastive
learning for detecting writing style changes in multi-author documents. Similarly, Huang et al. [9]
proposed an encoded classifier using knowledge distillation, leveraging a large pre-trained model as the
teacher to train a smaller student model for style change detection.
      Regularization techniques are critical in enhancing the generalization capabilities of neural net-
works by preventing overfitting, especially on small datasets. Traditional methods such as L2 regular-
ization, dropout, and early stopping have been widely used to improve model robustness. Dropout, in
particular, randomly sets a fraction of the input units to zero during training, which helps in preventing
co-adaptation of hidden units.
      Building on the concept of dropout, R-Drop (Regularized Dropout) is a more recent technique
proposed by Liang et al. [6]. R-Drop enhances regularization by applying dropout twice during training
and minimizing the divergence between the two forward passes. This approach encourages the model
to produce consistent outputs despite the dropout noise, thereby learning more robust representations.
      In the context of multi-author writing style analysis, R-Drop can be particularly beneficial when
combined with pre-trained language models. The regularization helps mitigate overfitting on training
datasets, which is often a challenge in style change detection tasks. By ensuring that the model maintains
consistent outputs despite the dropout noise, R-Drop enhances the robustness of the learned writing
style representations.


3. Methods
     In the Multi-Author Writing Style Analysis task, our goal is to identify points within a document
where the author changes, using variations in writing style as indicators. We use a model based
on the base version of the DeBERTa-v3 model combined with R-Drop regularization. We trained
the base version of the DeBERTa-v3 model independently on three different datasets representing
varying difficulty levels, using R-Drop during training to enhance the model’s performance by reducing
uncertainty and improving generalization.

3.1. Encoder and Classifier
     We used the base version of the DeBERTa-v3 model as the encoder, which excels in capturing
language structures and patterns. DeBERTa utilizes enhanced decoding and disentangled attention
mechanisms to better understand contextual information. On top of DeBERTa-v3, we added a binary
classification layer to detect style changes between paragraphs. This layer is trained using a loss
function that combines cross-entropy loss and KL divergence for enhanced regularization, as described
in the R-Drop regularization.

3.2. R-Drop regularization
     The R-Drop method (Regularized Dropout) aims to reduce model uncertainty by introducing
dual regularization during training. Specifically, for each training batch, we perform two forward
and backward passes and calculate the KL divergence between the two forward pass results as a
regularization term. The core formula is as follows:

                                          𝐿total = 𝐿ce + 𝛼𝐿kl

where 𝐿ce is the cross-entropy loss, 𝐿kl is the KL divergence between the two forward pass results, and
𝛼 is the weighting parameter.
     Given the input data 𝑥𝑖 at each training step, we feed 𝑥𝑖 through the forward pass of the network
twice, obtaining two distributions of the model predictions, denoted as 𝑃𝑤1 (𝑦𝑖 |𝑥𝑖 ) and 𝑃𝑤2 (𝑦𝑖 |𝑥𝑖 ).
Since the dropout operator randomly drops units in a model, the two forward passes are based on two
different sub models. The KL divergence between these two output distributions is then calculated as
follows:
                      1
               𝐿kl = (𝐷KL (𝑃𝑤1 (𝑦𝑖 |𝑥𝑖 )‖𝑃𝑤2 (𝑦𝑖 |𝑥𝑖 )) + 𝐷KL (𝑃𝑤2 (𝑦𝑖 |𝑥𝑖 )‖𝑃𝑤1 (𝑦𝑖 |𝑥𝑖 )))
                      2
where 𝐷KL denotes the Kullback-Leibler divergence.

3.3. DeBERTa-v3 with R-Drop regularization
     As Algorithm 1 demonstrates, the training process for DeBERTa-v3 with R-Drop regularization
includes data input, model training, and model parameters output, ensuring a comprehensive under-
standing of the method. We start by loading and preprocessing the data, splitting it into training,
validation, and test sets. The preprocessed paragraph pairs are then input into the model. We fine-tune
the DeBERTa-v3-base model on the training data using the R-Drop method. This method involves
performing two forward and backward passes for each training batch and calculating the KL divergence
between the two forward pass results as a regularization term, helping to reduce model uncertainty
and improve robustness.
     During training, for each batch, we compute the forward pass twice with dropout, calculate the
cross-entropy and KL divergence losses, and update the model parameters. Early stopping [10] is
implemented based on the evaluation set to prevent overfitting, monitoring the validation loss and
halting training when it ceases to improve. We assess the model’s performance on the validation set
using the F1-score to measure its effectiveness. Finally, we evaluate the final model on the test set to
measure its overall performance.

Algorithm 1 Training Process for DeBERTa-v3 with R-Drop regularization
 1: Input: Number of training epochs 𝑒𝑝𝑜𝑐ℎ𝑠, Training data loader 𝑡𝑟𝑎𝑖𝑛_𝑙𝑜𝑎𝑑𝑒𝑟, Validation data
    loader 𝑣𝑎𝑙_𝑙𝑜𝑎𝑑𝑒𝑟, Loss function 𝑙𝑜𝑠𝑠_𝑓 𝑐𝑡, Weighting parameter 𝛼, Optimizer 𝑜𝑝𝑡𝑖𝑚𝑖𝑧𝑒𝑟, Evalua-
    tion step 𝑒𝑣𝑎𝑙_𝑠𝑡𝑒𝑝
 2: Output: Trained model parameters 𝜃
 3: Initialize model parameters 𝜃 with initial values
 4: for epoch 𝑒 in range 𝑒𝑝𝑜𝑐ℎ𝑠 do
 5:     for each batch (𝑥, 𝑦) in 𝑡𝑟𝑎𝑖𝑛_𝑙𝑜𝑎𝑑𝑒𝑟 do
 6:          Set model to training mode
 7:          Compute model output 𝑜𝑢𝑡𝑝𝑢𝑡1 for the current batch 𝑥
 8:          Compute model output 𝑜𝑢𝑡𝑝𝑢𝑡2 for the current batch 𝑥
 9:          Calculate the cross-entropy loss 𝐿𝑐𝑒 = 0.5 · (𝑙𝑜𝑠𝑠_𝑓 𝑐𝑡(𝑜𝑢𝑡𝑝𝑢𝑡1, 𝑦) + 𝑙𝑜𝑠𝑠_𝑓 𝑐𝑡(𝑜𝑢𝑡𝑝𝑢𝑡2, 𝑦))
10:          Compute the KL divergence loss 𝐿𝑘𝑙 = 𝑐𝑜𝑚𝑝𝑢𝑡𝑒_𝑘𝑙_𝑙𝑜𝑠𝑠(𝑜𝑢𝑡𝑝𝑢𝑡1, 𝑜𝑢𝑡𝑝𝑢𝑡2)
11:          Combine the losses: 𝐿𝑡𝑜𝑡𝑎𝑙 = 𝐿𝑐𝑒 + 𝛼 · 𝐿𝑘𝑙
12:          Perform backpropagation and update model parameters using 𝑜𝑝𝑡𝑖𝑚𝑖𝑧𝑒𝑟
13:          if current step % 𝑒𝑣𝑎𝑙_𝑠𝑡𝑒𝑝 == 0 then
14:              Evaluate the model on validation data
15:          end if
16:     end for
17: end for
18: Return: Trained model parameters 𝜃
4. Experiments
4.1. Datasets
      The datasets were provided by the PAN (Plagiarism Analysis, Authorship Identification, and
Near-Duplicate Detection) initiative as part of the PAN 2024 lab at CLEF (Conference and Labs of the
Evaluation Forum). The datasets used for this task are derived from Reddit comments, combined into
documents that represent different levels of difficulty. These datasets are designed to test the models’
ability to detect style changes under various conditions of topical similarity. Each dataset is split into
three subsets: training, validation, and test sets, with respective proportions of 70%, 15%, and 15%. The
difficulty levels of the task are as follows:

    • Easy: This dataset consists of documents where the paragraphs cover a wide variety of topics.
      The diverse topics make it easier for models to leverage topic changes as signals for detecting
      authorship changes.
    • Medium: The documents in this dataset have a limited number of topics, requiring models
      to focus more on subtle changes in writing style rather than topic shifts to detect changes in
      authorship.
    • Hard: All paragraphs in the documents within this dataset are on the same topic. This scenario
      poses the greatest challenge as the models must rely entirely on stylistic differences to identify
      authorship changes

4.2. Experimental Setup
      For our experiments, our preprocessing of the data involves several key steps. First, the dataset is
loaded, and each document is read. The documents are then split into natural paragraphs. Following
this, we generate pairs of consecutive paragraphs and label each pair to indicate whether there is a
style change between them. This labeling transforms the task into a binary classification problem. Each
labeled pair of paragraphs is then used as an input for the training of our model. These steps result in
the creation of features and labels for the training, validation, and test sets, which are used for model
training and evaluation.
      We utilized the DeBERTa-v3-base(the base version of the DeBERTa-v3 mode) and DeBERTa-v3-
base+R-Drop models. The DeBERTa-v3-base model served as our baseline, whereas the DeBERTa-v3-
base+R-Drop model incorporated the R-Drop regularization technique to enhance performance by
reducing variance between different forward passes. For all three datasets, the R-Drop hyperparameters
were set as follows: kl_alpha, was set to 5 based on the experimental results from the original paper [6].
The Dropout rate was set to 0.1, which is the default value for DeBERTa-v3-Base.
      The DeBERTa-v3-base+R-Drop model was fine-tuned on the training sets using the Adam opti-
mizer [11] with a learning rate of 1 × 10−5 . The batch size was set to 16, and the models were trained
for 10 epochs. To prevent overfitting, early stopping was implemented based on the validation loss.
Additionally, we included results from two simple baselines: one where the prediction is always 1 and
another where the prediction is always 0 [12], and compared these to the outcomes from our models on
the test dataset.
      Evaluation of the models was conducted using the F1-score on both the validation and test sets.
The F1-score was chosen as the primary metric due to its balance between precision and recall, which
is crucial for accurately detecting changes in writing style.

4.3. Results
     In Table 1, we report the F1 scores on the validation set for the multi-author writing style analysis
task. We present the scores for the validation and test sets, comparing the performance of DeBERTa-
v3-base and DeBERTa-v3-base+R-Drop.The results show that the DeBERTa-v3-base+R-Drop model
generally outperforms the baseline DeBERTa-v3-base model across all difficulty levels on the validation
set. However, this improvement is more noticeable in the Easy category compared to the Medium and
Hard categories.
      The Easy category shows a significant performance boost, which might be attributed to the R-Drop
regularization reducing overfitting and enhancing model stability. On the other hand, the performance
gains in the Medium and Hard categories are relatively modest. This could be due to the increased
complexity and reduced topical variety in these categories, which pose a greater challenge for the
model. The smaller performance gains suggest that while R-Drop helps, it might not fully address the
intricacies involved in these more difficult tasks.

Table 1
F1 scores on validation set for multi-author writing style analysis task using DeBERTa-v3 and DeBERTa-v3 +
R-Drop. The tasks included Task 1 (easy dataset), Task 2 (medium dataset), and Task 3 (hard dataset).
                           Approach                     Task 1 Task 2 Task 3
                           DeBERTa-v3-base               96.9       83.8       83.5
                           DeBERTa-v3-base+R-Drop        98.7       84.1       84.1


    In Table 2, we report the F1 scores on the test set for the multi-author writing style analysis task.
The DeBERTa-v3-base+R-Drop model maintains its performance, but with noticeable variability in the
Medium and Hard categories. This variability indicates that the model’s generalization capability, while
improved by R-Drop, still faces challenges with more complex and less distinct style changes.

Table 2
F1 scores on test set for multi-author writing style analysis task using DeBERTa-v3 and two sample baselines.
The tasks included Task 1 (easy dataset), Task 2 (medium dataset), and Task 3 (hard dataset).
                                Approach             Task 1 Task 2 Task 3
                                DEBERTA+R-drop       0.985      0.815      0.826
                                Baseline Predict 1   0.466      0.343      0.320
                                Baseline Predict 0   0.112      0.323      0.346




5. Conclusion
     Our study shows that combining the base version of the DeBERTa-v3 model with R-Drop regu-
larization significantly improves the accuracy of detecting authorship changes across documents of
varying difficulty. We trained the model on datasets with different levels of topic diversity, showing
marked improvements particularly in documents with diverse topics. However, in documents with
limited topical diversity, performance gains are modest, indicating the need for further refinement.
Future work should focus on enhancing model performance in more complex scenarios and exploring
complementary methods to address the identified challenges.


Acknowledgments
     This work is supported by the National Social Science Foundation of China (22BTQ101)


References
 [1] E. Zangerle, M. Mayerl, M. Potthast, B. Stein, Overview of the Multi-Author Writing Style Analysis
     Task at PAN 2024, in: G. Faggioli, N. Ferro, P. Galuščáková, A. G. S. de Herrera (Eds.), Working
     Notes of CLEF 2024 - Conference and Labs of the Evaluation Forum, CEUR-WS.org, 2024.
 [2] M. E. Peters, M. Neumann, M. Iyyer, M. Gardner, C. Clark, K. Lee, L. Zettlemoyer, Deep contex-
     tualized word representations, in: M. A. Walker, H. Ji, A. Stent (Eds.), Proceedings of the 2018
     Conference of the North American Chapter of the Association for Computational Linguistics:
     Human Language Technologies, NAACL-HLT 2018, New Orleans, Louisiana, USA, June 1-6, 2018,
     Volume 1 (Long Papers), Association for Computational Linguistics, 2018, pp. 2227–2237. URL:
     https://doi.org/10.18653/v1/n18-1202. doi:10.18653/V1/N18-1202.
 [3] A. Vaswani, N. Shazeer, N. Parmar, J. Uszkoreit, L. Jones, A. N. Gomez, L. Kaiser, I. Polosukhin,
     Attention is all you need, in: I. Guyon, U. von Luxburg, S. Bengio, H. M. Wallach, R. Fergus,
     S. V. N. Vishwanathan, R. Garnett (Eds.), Advances in Neural Information Processing Systems
     30: Annual Conference on Neural Information Processing Systems 2017, December 4-9, 2017,
     Long Beach, CA, USA, 2017, pp. 5998–6008. URL: https://proceedings.neurips.cc/paper/2017/hash/
     3f5ee243547dee91fbd053c1c4a845aa-Abstract.html.
 [4] J. Devlin, M. Chang, K. Lee, K. Toutanova, BERT: pre-training of deep bidirectional transformers
     for language understanding, in: J. Burstein, C. Doran, T. Solorio (Eds.), Proceedings of the 2019
     Conference of the North American Chapter of the Association for Computational Linguistics:
     Human Language Technologies, NAACL-HLT 2019, Minneapolis, MN, USA, June 2-7, 2019, Volume
     1 (Long and Short Papers), Association for Computational Linguistics, 2019, pp. 4171–4186. URL:
     https://doi.org/10.18653/v1/n19-1423. doi:10.18653/V1/N19-1423.
 [5] P. He, X. Liu, J. Gao, W. Chen, Deberta: decoding-enhanced bert with disentangled attention, in:
     9th International Conference on Learning Representations, ICLR 2021, Virtual Event, Austria, May
     3-7, 2021, OpenReview.net, 2021. URL: https://openreview.net/forum?id=XPZIaotutsD.
 [6] X. Liang, L. Wu, J. Li, Y. Wang, Q. Meng, T. Qin, W. Chen, M. Zhang, T. Liu, R-drop:
     Regularized dropout for neural networks, in: M. Ranzato, A. Beygelzimer, Y. N. Dauphin,
     P. Liang, J. W. Vaughan (Eds.), Advances in Neural Information Processing Systems 34: An-
     nual Conference on Neural Information Processing Systems 2021, NeurIPS 2021, December 6-
     14, 2021, virtual, 2021, pp. 10890–10905. URL: https://proceedings.neurips.cc/paper/2021/hash/
     5a66b9200f29ac3fa0ae244cc2a51b39-Abstract.html.
 [7] Y. Liu, M. Ott, N. Goyal, J. Du, M. Joshi, D. Chen, O. Levy, M. Lewis, L. Zettlemoyer, V. Stoyanov,
     Roberta: A robustly optimized BERT pretraining approach, volume abs/1907.11692, 2019. URL:
     http://arxiv.org/abs/1907.11692. arXiv:1907.11692.
 [8] H. Chen, Z. Han, Z. Li, Y. Han, A writing style embedding based on contrastive learning for
     multi-author writing style analysis, in: M. A. andf Guglielmo Faggioli, N. Ferro, M. Vlachos (Eds.),
     Working Notes of the Conference and Labs of the Evaluation Forum (CLEF 2023), Thessaloniki,
     Greece, September 18th to 21st, 2023, volume 3497 of CEUR Workshop Proceedings, CEUR-WS.org,
     2023, pp. 2562–2567. URL: https://ceur-ws.org/Vol-3497/paper-206.pdf.
 [9] M. Huang, Z. Huang, L. Kong, Encoded classifier using knowledge distillation for multi-author
     writing style analysis, in: M. Aliannejadi, G. Faggioli, N. Ferro, M. Vlachos (Eds.), Working Notes
     of the Conference and Labs of the Evaluation Forum (CLEF 2023), Thessaloniki, Greece, September
     18th to 21st, 2023, volume 3497 of CEUR Workshop Proceedings, CEUR-WS.org, 2023, pp. 2629–2634.
     URL: https://ceur-ws.org/Vol-3497/paper-214.pdf.
[10] R. Caruana, S. Lawrence, C. L. Giles, Overfitting in neural nets: Backpropagation, conjugate
     gradient, and early stopping, in: T. K. Leen, T. G. Dietterich, V. Tresp (Eds.), Advances in Neural
     Information Processing Systems 13, Papers from Neural Information Processing Systems (NIPS)
     2000, Denver, CO, USA, MIT Press, 2000, pp. 402–408. URL: https://proceedings.neurips.cc/paper/
     2000/hash/059fdcd96baeb75112f09fa1dcc740cc-Abstract.html.
[11] D. P. Kingma, J. Ba, Adam: A method for stochastic optimization, in: Y. Bengio, Y. LeCun (Eds.),
     3rd International Conference on Learning Representations, ICLR 2015, San Diego, CA, USA, May
     7-9, 2015, Conference Track Proceedings, 2015. URL: http://arxiv.org/abs/1412.6980.
[12] M. Fröbe, M. Wiegmann, N. Kolyada, B. Grahm, T. Elstner, F. Loebe, M. Hagen, B. Stein, M. Potthast,
     Continuous Integration for Reproducible Shared Tasks with TIRA.io, in: J. Kamps, L. Goeuriot,
     F. Crestani, M. Maistro, H. Joho, B. Davis, C. Gurrin, U. Kruschwitz, A. Caputo (Eds.), Advances
     in Information Retrieval. 45th European Conference on IR Research (ECIR 2023), Lecture Notes
in Computer Science, Springer, Berlin Heidelberg New York, 2023, pp. 236–241. doi:10.1007/
978-3-031-28241-6_20.