Noise and Its Impact on Language Models
Examining how noise affects the understanding of language models.
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Table of Contents
Language models are tools that help computers understand and generate human language. They are trained on large amounts of text to learn the meanings of words and how they are used in sentences. However, these models can struggle when faced with errors or “Noise” in the text. Noise can come from typos, slang, or unusual spelling, which can confuse these models and lead to misunderstandings.
The Basics of Language Models
Language models break down words into smaller parts called subwords. This is done to better understand the different meanings of parts of words. For example, the word "unhappiness" can be broken into "un" and "happiness." This method helps the model learn how different components contribute to the overall meaning.
Despite their sophistication, language models have limits. When they encounter noise, such as a typo or a made-up subword, they can struggle to keep the meaning of words clear. This is especially true if the noise disrupts the subword segmentation.
Types of Noise and Their Impact
Noise can take many forms, such as:
Complete Corruption: This happens when none of the original segments are present in the noisy version. For example, if "happy" becomes "xyz," the model has no idea what the word means anymore.
Partial Corruption: This is when some parts of the original word are still there but are mixed with noise. For example, "happy" might turn into "hapyy." The model might still understand some of the meaning here.
Additive Noise: This occurs when extra parts are added to a word without changing the original parts. An example is when "happy" becomes "happyy." The model might get confused because of the added letters.
Intact Corruption: In this case, the original word is changed in a way that it still keeps a similar form. For example, "great" could turn into "grate," which is not the same word but might still have a familiar look.
Why Does This Matter?
Understanding how noise affects language models is essential for their improvement. If we know how models react to mistakes, we can work on making them better at handling real-world language, which is filled with errors and variations.
For practical uses like translating languages or analyzing emotions in text, we want models to correctly interpret words no matter the noise. Nobody types perfectly, especially on social media where typos and slang are common.
The Role of Subword Segmentation
Subword segmentation is critical for models to understand words correctly. When noise disrupts this segmentation, models may not be able to figure out the meaning accurately. For example, if "wonderful" becomes "wondrfl," the model might not understand it at all.
Research shows that models that break down words into subwords react poorly to noise, while those that look at the entire word do better. This indicates that maintaining the correct segments is vital for comprehension.
Experiment Insights
Experiments have been carried out to see how well language models handle different kinds of noise. The findings suggest:
- When a word is completely corrupted, models fail to understand it at all.
- If models can retain larger parts of a word, they do better than when only small fragments are kept.
- Even if all original parts are present, adding too many extra letters can confuse the models and lead to a misunderstanding of the meaning.
Across different types of models, these patterns remain consistent, showing a clear need for subword preservation to keep word meanings intact.
Creating Noisy Datasets
To test how noise affects words, researchers create special datasets with both normal and noisy versions of words. This way, they can systematically evaluate how well models understand the noisy words compared to their original forms.
These datasets contain words that have been altered using different noise models. For example, some words may have their letters swapped around, while others might have randomly added letters. By analyzing how models respond to these changes, researchers gain valuable insights into which factors lead to misunderstandings.
Evaluating Performance
When testing models, researchers look at how accurately the models classify words. By examining their responses to noisy words, they can see if the models still hold on to the correct meanings.
For example, if a model correctly identifies the sentiment of the word "happy" but fails with "hapyy," it shows the impact that noise has on performance. Through this, researchers can pinpoint what makes certain words more vulnerable to misinterpretation.
The Importance of Context
Context plays a significant role in how well language models understand words. Even with noise, if a word is used in a recognizable context, models may still retain some understanding. For instance, if "happy" is framed within a sentence about feeling good, a model might still get the general idea even if it is misspelled.
Additionally, some words have more than one meaning depending on their context. Models that can use context effectively may perform better under noisy conditions, suggesting that training them to consider surrounding words can improve their understanding.
Looking Ahead
Moving forward, researchers aim to build models that can better handle real-world language, which is messy and full of errors. This includes fine-tuning models so they learn to expect noise and adjust their understanding accordingly.
There is also a push to explore different kinds of language models beyond current popular choices to see how they react to noise. By studying various models, researchers hope to identify new strategies for improving performance.
Conclusion
Noise in language can significantly affect how language models perceive and interpret words. From complete corruption to small alterations, understanding these impacts is crucial for developing better models. Future work will continue to focus on enhancing how these tools interact with the messy reality of human language, ensuring they remain effective in understanding and generating text even amidst errors.
Title: Can Pretrained Language Models Derive Correct Semantics from Corrupt Subwords under Noise?
Abstract: For Pretrained Language Models (PLMs), their susceptibility to noise has recently been linked to subword segmentation. However, it is unclear which aspects of segmentation affect their understanding. This study assesses the robustness of PLMs against various disrupted segmentation caused by noise. An evaluation framework for subword segmentation, named Contrastive Lexical Semantic (CoLeS) probe, is proposed. It provides a systematic categorization of segmentation corruption under noise and evaluation protocols by generating contrastive datasets with canonical-noisy word pairs. Experimental results indicate that PLMs are unable to accurately compute word meanings if the noise introduces completely different subwords, small subword fragments, or a large number of additional subwords, particularly when they are inserted within other subwords.
Authors: Xinzhe Li, Ming Liu, Shang Gao
Last Update: 2023-06-27 00:00:00
Language: English
Source URL: https://arxiv.org/abs/2306.15268
Source PDF: https://arxiv.org/pdf/2306.15268
Licence: https://creativecommons.org/licenses/by/4.0/
Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.
Thank you to arxiv for use of its open access interoperability.
Reference Links
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