Reducing the cost of annotation: automation, active learning, and more

Automation and active learning allow organizations to scale their efforts while scaling down annotation costs and time, maintaining high quality. Combining cutting-edge technologies with expert review allows for the best results.
Active learning enables companies to perform highly with less data, resulting in fewer annotations and faster deployment times.
Next, we'll see how innovative methods change the data labeling process.
Quick Take
- Automation technologies reduce annotation time and cost.
- Strategic frame selection reduces video annotations.
- Focusing on critical cases improves AI model performance in complex scenarios.
- Combining automation and annotator validation ensures optimal annotation results.

Understanding Annotation Overhead
Annotation overhead is the additional resources (time, money, effort) required not for the annotation process but to ensure its quality.
Why it matters for data labeling
Overhead is important for data labeling because it affects annotation quality, consistency, and efficiency. Ignoring this overhead will result in poor quality, inconsistent, or mislabeled data, which will lead to poor performance of AI models.
So, investing in overhead is investing in the reliability and accuracy of the data and, ultimately, the success of the entire NLP project.
Impact on Machine Learning Projects
Overhead affects the scalability and cost-effectiveness of machine learning projects. Annotation management systems support various functions:
The Role of Automation in Annotation
Automation reduces manual labor, increases speed, and improves consistency — resulting in significant overhead reduction in data labeling projects. Automation includes:
- Pre-annotation. An AI model automatically adds labels, and the annotator checks or corrects.
- Rules and templates. Used for repetitive structures or simple tasks.
- Interactive prompts. Tools that "learn" from previous labels and help annotators.
- Automatic detection of errors or inconsistencies. Used to check the quality of the annotation.
This is important when working with large datasets, where manual labeling is time-consuming. Automation reduces project time and allows teams to focus on more complex or subjective cases that require human expertise.
Active Learning Strategies
Active learning is an approach in machine learning where an AI model selects the most relevant examples from unannotated data for human annotation.
Implementing Active Learning Models
To implement active learning models, the following methods are used:
- Uncertainty sampling. The AI model selects examples where it is less confident in its predictions.
- Request from the committee. Multiple models are created, and the examples with the largest prediction difference are selected.
- Marginal sampling. Focuses on examples close to the decision boundary
These strategies help to accurately identify important data points, improve AI model performance, and minimize labeling effort.

Crowdsourcing vs. In-house Annotation
Each method has advantages and disadvantages, affecting both the overhead and the quality of the result. Let's compare their advantages.
Methods for Faster Annotation
We use advanced tools and methods to speed up annotation. The Keymakr platform has optimized user interfaces and keyboard shortcuts, which allow annotators to work quickly. We also use tools with built-in AI to reduce manual effort. This combination has resulted in time savings in data annotation projects.
Detailed instructions
Thanks to detailed instructions, annotators are consistent in data annotation. Instructions for each project, including examples and rare cases. This helps annotators make quick and accurate decisions, increasing the efficiency of data labeling.
Annotator training
Training is the key to reducing annotation time. Combining theoretical and practical training helps you learn and consolidate new information in the work. It also helps you understand the requirements of a specific project, recognize typical pitfalls, and apply practices for speed and accuracy.
Using AI for annotations
With AI-based tools, computer vision and natural language processing models independently pre-label images, videos, audio, and text. This speeds up the creation of datasets for training AI models, especially in areas with huge data.
The AI performs only the pre-annotation, and the annotators perform the checking and correction. This approach combines machines' speed with humans' accuracy and is the basis of the human-in-the-loop concept. Human thought allows us to check the annotations and use the errors of the AI model for further training.
Data Annotation Quality Control
Quality control is essential for creating accurate AI training datasets. It helps to detect errors early, saving time and resources.
- Implement quality control processes.
- Establish clear guidelines for data annotation.
- Use automated checks to flag common errors.
- Implement a multi-level verification system.
- Regularly train and review annotators.
These techniques maintain consistency and accuracy while minimizing overhead.
Common Pitfalls and How to Avoid Them
Annotation projects often encounter issues that can compromise quality. Let's consider common pitfalls and strategies for avoiding them:
Measuring Annotation Performance
These metrics are used to assess annotation performance:
- Annotation rate (items per hour).
- Error rate (percentage of incorrect labels).
- Concordance score (agreement between annotators).
- Task performance metrics.
- Quality control throughput metrics.
- Performance monitoring tools.
Tools exist to help track annotation performance. They identify bottlenecks and improve workflows.
Properly assessing annotation performance and efficiency helps make informed decisions. This improves the data labeling process and, ultimately, the quality of machine learning models.
Future trends in annotation techniques
The field of data annotation is evolving rapidly. Looking ahead, new annotation methods will change the way data is prepared for AI models. The goal is to reduce manual effort while maintaining quality.
Development of semantic annotation that will allow not only to label words by parts of speech or classes but also to understand them semantically — that is, to annotate meaning, context, and intent.
Combining active learning with LLM models (like GPT) helps filter out the most ambiguous or important fragments of text for the model — with a focus on context, not just words.
Real-time annotation through assistant models generates the initial annotation, and a person only verifies or corrects. The AI model "learns" in the process.
Multimodal text annotation considers images, video, and audio accompanying text—for example, a caption for a photo or a text description for video analysis.
Ethical and culturally aware annotation that addresses cultural nuances, stereotypes, and biases in text. Models learn to "see" offensive or biased content and annotate it according to ethical norms. Zero-shot / few-shot annotation enables AI models to be trained on few examples or none, using knowledge from large language models (LLMs).
FAQ
What is annotation overhead, and why is it important?
Annotation overhead is the resources spent on training, quality control, and managing the data annotation process. It is important because it affects the overall cost of developing AI systems and the quality of AI models trained on that data.
How does automation help reduce annotation costs?
Automation reduces annotation costs by automatically generating initial annotations.
What is active learning, and how does it benefit annotation processes?
Active learning is an approach where an AI model selects relevant examples for manual annotation. This reduces the amount of annotation by focusing efforts on complex or ambiguous data.
How can the efficiency of data annotation processes be improved?
Active learning reduces the amount of annotation required by selecting the most relevant examples. It also uses pre-trained AI models for automatic pre-annotation with subsequent human validation.
What role does AI play in improving annotation processes?
AI-powered tools help with this. They pre-label data, render annotations in real time, and improve efficiency.
What KPIs should be tracked to assess annotation performance?
Metrics include annotation speed, accuracy, consistency, and annotations per unit of time.
What future trends should we anticipate in annotation techniques?
Future trends include the development of semantic annotation, context-aware active learning, real-time annotation through assistant models, multimodal text annotation, and ethical and culturally aware annotation.
