Synthetic data, artificially generated to mimic real data, plays a crucial role in various applications, including machine learning, data analysis, testing, and privacy protection. In Natural Language Processing (NLP), synthetic data proves invaluable for enhancing training sets, particularly in low-resource languages, domains, and tasks, thereby enhancing the performance and robustness of NLP models. However, generating synthetic data for NLP is non-trivial, demanding high linguistic knowledge, creativity, and diversity.
Different methods, such as rule-based and data-driven approaches, have been proposed to generate synthetic data. However, these methods have limitations, such as data scarcity, quality issues, lack of diversity, and domain adaptation challenges. Therefore, we need innovative solutions to generate high-quality synthetic data for specific languages.
A significant improvement in generating synthetic data includes adjusting models for different languages. This means building models for each language so that the synthetic data generated is more accurate and realistic in reflecting how people use those languages. It is like teaching a computer to understand and mimic different languages’ unique patterns and details, making synthetic data more valuable and reliable.
The Evolution of Synthetic Data Generation in NLP
NLP tasks, such as machine translation, text summarization, sentiment analysis, etc., require a lot of data to train and evaluate the models. However, obtaining such data can be challenging, especially for low-resource languages, domains, and tasks. Therefore, synthetic data generation can help augment, supplement, or replace accurate data in NLP applications.
The techniques for generating synthetic data for NLP have evolved from rule-based to data-driven to model-based approaches. Each approach has its features, advantages, and limitations, and they have contributed to the progress and challenges of synthetic data generation for NLP.
Rule-based Approaches
Rule-based approaches are the earliest techniques that use predefined rules and templates to generate texts that follow specific patterns and formats. They are simple and easy to implement but require a lot of manual effort and domain knowledge and can only generate a limited amount of repetitive and predictable data.
Data-driven Approaches
These techniques use statistical models to learn the probabilities and patterns of words and sentences from existing data and generate new texts based on them. They are more advanced and flexible but require a large amount of high-quality data and may create texts that need to be more relevant or accurate for the target task or domain.
Model-based Approaches
These state-of-the-art techniques that use Large Language Models (LLMs) like BERT, GPT, and XLNet present a promising solution. These models, trained on extensive text data from diverse sources, exhibit significant language generation and understanding capabilities. The models can generate coherent, diverse texts for various NLP tasks like text completion, style transfer, and paraphrasing. However, these models may not capture specific features and nuances of different languages, especially those under-represented or with complex grammatical structures.
A new trend in synthetic data generation is tailoring and fine-tuning these models for specific languages and creating language-specific foundation models that can generate synthetic data that is more relevant, accurate, and expressive for the target language. This can help bridge the gaps in training sets and improve the performance and robustness of NLP models trained on synthetic data. However, this also has some challenges, such as ethical issues, bias risks, and evaluation challenges.
How Can Language-Specific Models Generate Synthetic Data for NLP?
To overcome the shortcomings of current synthetic data models, we can enhance them by tailoring them to specific languages. This involves pre-training text data from the language of interest, adapting through transfer learning, and fine-tuning with supervised learning. By doing so, models can enhance their grasp of vocabulary, grammar, and style in the target language. This customization also facilitates the development of language-specific foundation models, thereby boosting the accuracy and expressiveness of synthetic data.
LLMs are challenged to create synthetic data for specific areas like medicine or law that need specialized knowledge. To address this, techniques include using domain-specific languages (e.g., Microsoft’s PROSE), employing multilingual BERT models (e.g., Google’s mBERT) for various languages, and utilizing Neural Architecture Search (NAS) like Facebook’s AutoNLP to enhance performance have been developed. These methods help produce synthetic data that fits well and is of superior quality for specific fields.
Language-specific models also introduce new techniques to enhance the expressiveness and realism of synthetic data. For example, they use different tokenization methods, such as Byte Pair Encoding (BPE) for subword tokenization, character-level tokenization, or hybrid approaches to capture language diversity.
Domain-specific models perform well in their respective domains, such as BioBERT for biomedicine, LegalGPT for law, and SciXLNet for science. Additionally, they integrate multiple modalities like text and image (e.g., ImageBERT), text and audio (e.g., FastSpeech), and text and video (e.g., VideoBERT) to enhance diversity and innovation in synthetic data applications.
The Benefits of Synthetic Data Generation with Language-specific Models
Synthetic data generation with language-specific models offers a promising approach to address challenges and enhance NLP model performance. This method aims to overcome limitations inherent in existing approaches but has drawbacks, prompting numerous open questions.
One advantage is the ability to generate synthetic data aligning more closely with the target language, capturing nuances in low-resource or complex languages. For example, Microsoft researchers demonstrated enhanced accuracy in machine translation, natural language understanding, and generation for languages like Urdu, Swahili, and Basque.
Another benefit is the capability to generate data tailored to specific domains, tasks, or applications, addressing challenges related to domain adaptation. Google researchers highlighted advancements in named entity recognition, relation extraction, and question answering.
In addition, language-specific models enable the development of techniques and applications, producing more expressive, creative, and realistic synthetic data. Integration with multiple modalities like text and image, text and audio, or text and video enhances the quality and diversity of synthetic data for various applications.
Challenges of Synthetic Data Generation with Language-specific Models
Despite their benefits, several challenges are pertinent to language-specific models in synthetic data generation. Some of the challenges are discussed below:
An inherent challenge in generating synthetic data with language-specific models is ethical concerns. The potential misuse of synthetic data for malicious purposes, like creating fake news or propaganda, raises ethical questions and risks to privacy and security.
Another critical challenge is the introduction of bias in synthetic data. Biases in synthetic data, unrepresentative of languages, cultures, genders, or races, raise concerns about fairness and inclusivity.
Likewise, the evaluation of synthetic data poses challenges, particularly in measuring quality and representativeness. Comparing NLP models trained on synthetic data versus real data requires novel metrics, hindering the accurate assessment of synthetic data’s efficacy.
The Bottom Line
Synthetic data generation with language-specific models is a promising and innovative approach that can improve the performance and robustness of NLP models. It can generate synthetic data that is more relevant, accurate, and expressive for the target language, domain, and task. Additionally, it can enable the creation of novel and innovative applications that integrate multiple modalities. However, it also presents challenges and limitations, such as ethical issues, bias risks, and evaluation challenges, which must be addressed to utilize these models’ potential fully.