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The Struggle with data labeling in machine learning

Nov 10th, 2023

Machine learning heavily relies on data, and the fundamental processes of data annotation and labeling are what empower machines not just to acquire data but also to comprehend it and accurately categorize it. In this article , we embark on a journey into the domain of data labeling, where a thorough understanding of the various labeling types is of utmost importance. These labeling methods cater to a wide array of tasks, each with its unique purpose and contribution to the broader realm of data annotation.Furthermore, we’ll delve into the intricate challenges that stem from the inherent subjectivity and objectivity present in data. We will navigate the intricacies of managing a workforce and closely scrutinize the pivotal role played by quality assurance. Additionally, we’ll shed light on the potential pitfalls that can emerge from an overreliance on automation, emphasizing the critical importance of striking a harmonious balance between automation and human expertise.

What is Data Labeling in Machine Learning ?

Data labeling in the context of machine learning refers to the essential process of identifying and assigning tags or labels to individual data samples. This practice is predominantly employed to prepare datasets for the training of machine learning models. While it can be executed manually, it is often expedited and facilitated by specialized software tools designed for this purpose. The primary objective of data labeling is to enhance the interpretability and usability of data, enabling machine learning algorithms to learn and make accurate predictions or classifications based on the labeled information. This critical step in the machine learning pipeline is integral to the development of robust and effective AI systems.

What is the type of data labeling?

In the world of machine learning, data labeling comes in various types, each designed for specific tasks and data. Here are some common types to label data:

1. Label text spans in Data Labeling

Proficiency in text labeling is crucial when utilizing your preferred NLP annotation tool. Whether your task involves tagging complete words, sentences, or any other text segment, the ability to label text spans is a fundamental requirement.

data labeling

2. Relation Extraction

Relation Extraction in natural language processing (NLP) involves finding and categorizing the connections between entities mentioned in text. It’s like figuring out family relationships between people or identifying who started a company based on the words in a text. This helps in tasks like finding answers to questions, searching for information, and building knowledge databases.

data labeling

3. Named Entity Recognition

Named Entity Recognition (NER) is a technique in natural language processing (NLP) that pulls out details from text. It focuses on spotting and classifying significant information in the text, referred to as named entities.

data labeling

4. Sentiment classification in Data Labeling

Sentiment classification during data labeling encompasses both text and audio data, extending to song lyrics, for instance. This process involves categorizing text or audio content based on the sentiments or emotions it conveys. It typically assigns labels such as “positive,” “negative,” or “neutral” to represent the prevailing sentiment in the material. This sentiment classification is valuable for understanding the emotional context in diverse forms of media, including written text, audio recordings, and even song lyrics.

data labeling

5. Document classification in Data Labeling

Document classification in data labeling involves organizing and categorizing documents based on their content and characteristics. This task aims to assign documents to specific classes or categories, making it easier to retrieve and manage information. It is a fundamental process in information management and retrieval, helping to keep large volumes of documents organized and accessible.

6.Object recognition

Image labeling plays a crucial role in object recognition tasks. Annotators delineate objects or areas of interest within an image and assign labels to these objects. For example, in a city street scene, annotators might label objects like “house,” “scooter,” “traffic sign,” and “pedestrian.” This process is fundamental for training machines to recognize and differentiate objects in images.

7. Speaker Identification in Data Labeling

This technique involves labeling and distinguishing various speakers within an audio recording. It is widely applied in transcription services, voice-activated assistants,and forensic investigations.

8. Language Identification

This task involves transcribing audio content and determining the language being spoken, which is essential for multilingual applications and transcription services. It can also extend to video content, making it valuable for various language-related applications.

What is The Struggle with Data Labeling in Machine learning?

Data labeling is a fundamental and often challenging aspect of machine learning. It involves the meticulous process of attaching tags, labels, or attributes to raw data to help AI models understand and categorize it accurately. This struggle with data labeling encompasses various complexities and considerations, from maintaining high dataset quality to addressing issues like automation dependence and inadequate quality assurance. In this exploration, we will delve into the multifaceted challenges and critical importance of data labeling in the context of machine learning.

1.Dataset quality

Ensuring high dataset quality is crucial, but it presents its own set of challenges. To maintain consistency and accuracy, you must ensure that data laborers have the capability to produce high quality datasets. There are two primary facets of dataset quality : subjective and objective, and both can lead to data quality concerns.

Subjective Data Quality:
Subjective data quality relates to situations where there is no one size fits all standard for labeling. It depends on the labelers’ domain expertise, language, geographic origins, and cultural influences, which can all shape how they perceive and categorize the data. For example, deciding whether a video scene is “funny” lacks a universally agreed upon answer. Various labels may provide different interpretations due to their individual biases, personal histories, and cultural backgrounds. Moreover, the same labeler might assign different labels when reevaluating the task.

Objective Data Quality:
In contrast to subjective data, objective data has a definitive and correct answer, but it is not without its challenges. There’s a potential issue that labelers may not possess the necessary expertise within a specific domain to provide accurate answers. For instance, when labeling leaves, do the laborers have the required knowledge to distinguish between healthy and diseased leaves? Furthermore, in the absence of clear guidelines, labelers may face difficulties in determining how to label individual data elements. For instance, they might grapple with whether to categorize an entire car as a single entity “car” or to label each of its components separately.

2.The lack of data security compliance in Data Labeling

The lack of data security compliance is a critical concern in today’s digital landscape. Failure to adhere to data privacy regulations like GDPR, DPA, and CCPA can lead to significant risks for both individuals and businesses. When companies do not implement robust security measures, sensitive personal data becomes vulnerable to unauthorized access, data breaches, and misuse.
Furthermore, the absence of data security compliance not only exposes individuals to privacy infringements but also poses a severe threat to a company’s reputation and financial well-being. Data breaches can result in costly legal penalties, damage to brand image, and loss of trust from customers and clients.

3.Workforce Management:

Efficient workforce management is a critical factor in the data labeling process. It determines the annotation team’s ability to handle extensive volumes of unstructured client data while maintaining high quality and security throughout the workflow.
Striking the right balance between expanding the workforce and providing adequate training and supervision is essential. Some companies have successfully handled data labeling internally, especially when dealing with smaller datasets. However, as data volumes grow, the demands on the workforce increase, making it a challenging task for businesses. This involves recruiting and training personnel, which can be a time-consuming process. Additionally, the ever-expanding dataset sizes may render in-house data labeling impractical.

4.Inefficient QA or no QA at all

Insufficient Quality Assurance (QA) or the complete absence of QA procedures is a considerable obstacle in the domain of data labeling. Data annotation, by its nature, is a manual process that requires continuous human expert oversight at all stages, starting with data collection and extending to the comprehensive data labeling process.

As automation technology advances, there is a risk that human involvement in QA processes may be disregarded. However, human expertise is indispensable for ensuring the precision and reliability of data labeling. Without robust QA measures, the potential for errors, inconsistencies, and data quality issues increases  significantly, which can have far reaching consequences for businesses and the accuracy of machine learning and AI models.

Efficient QA procedures not only involve human review but also the development of clear guidelines, standardized practices, and quality control mechanisms. These mechanisms are essential for maintaining data accuracy, enhancing model performance, and building trust in the data labeling process. Ignoring or downplaying QA in data labeling can compromise the quality and integrity of the labeled data, potentially leading to significant setbacks in various applications relying on this data.

5. Automation dependence

Automated data annotation has been around for some time, yet businesses often err by placing excessive reliance on it in their pursuit of time and cost efficiency. This task necessitates precise algorithms that can efficiently and accurately label data without the need for human intervention. However, the nuanced complexities of language interpretation present a formidable challenge when developing dependable algorithms for this purpose.

Moreover, automated annotation must contend with incomplete or erroneous data, further adding to the intricacy of the process. Solely depending on automation may result in inaccuracies and misinterpretations, which can have adverse effects on  various data-driven applications downstream. Therefore, while automation offers advantages, a balanced approach that combines automation with human oversight and tailored solutions is crucial for ensuring the utmost data accuracy and reliability.


In the realm of machine learning, data annotation and labeling emerge as the unsung heroes, bridging the gap between raw data and AI understanding. These processes are the foundation upon which artificial intelligence stands, enhancing
data clarity, quality, and security. As we navigate the intricate challenges of subjectivity, objectivity, workforce management, and the perils of automation reliance, it becomes evident that the balance between automation and human expertise is the key to success.
Data labeling, the practice of assigning labels to data samples, is the lifeblood of machine learning. It empowers machines to learn with depth and precision, forging a pathway to a more intelligent world.
The struggles in data labeling are not roadblocks but crucibles of innovation. They compel us to refine processes, seek solutions, and push the boundaries of what machines can achieve. Data annotation and labeling are not just processes; they are the very essence of machine learning, propelling us toward a future where AI understands not just data, but the intricacies of the human experience.