NLP Annotation services

Advanced Message Filtering for Platform Safety

Image

When user trust is at stake, platforms can’t afford to let harmful messages slip through.

A major classifieds company needed a reliable way to protect conversations on their platform — without slowing them down. To make that happen, Unidata provided high-precision annotation and validation for a smart filtering and classification system that now helps keep millions of daily interactions safe and respectful.

Image

Client Request

Our client, a leading company in the classifieds industry, aimed to build a message filtering system that would:

  • Prevent the spread of inappropriate or restricted content
  • Improve overall conversation quality on the platform
  • Protect users from violations such as:
    • Offensive or abusive language
    • Personal data disclosure
    • Negative or harmful speech

To achieve this, Unidata was brought in to annotate and validate the dataset, providing the foundation for a model that could reliably detect and categorize sensitive content.

Our Approach

Technical Requirements and Pilot Phase

The client provided a detailed technical brief outlining classification requirements. Our team proposed additional refinements to ensure a more precise and layered annotation process.

During the pilot phase, we collaborated closely with the client to:

  • Clarify classification rules for key categories, including:
    • Insults and abusive language
    • Mentions of personal information
    • References to meeting arrangements
    • Negative sentiment directed at the platform
  • Address complex edge cases, such as:
    • Implicit mentions of meeting locations (e.g., vague geographic references without full addresses)

Annotation and Quality Control Process

Our annotation team at Unidata handled classification by carefully considering:

  • Platform-specific communication patterns
  • Informal language use typical in peer-to-peer messaging
  • The context of each message, not just isolated phrases

Messages were annotated across several primary categories:

  • Use of profanities or slurs
  • Disclosure of personal or sensitive information
  • Various forms of direct and indirect insults
  • Mentions of meeting points or negotiation outside the platform

Data Validation

To ensure the highest level of annotation accuracy, we implemented a robust validation workflow:

  • Involved experienced validators to review annotated samples
  • Introduced an interactive error analysis process, which included:
    • Team discussions of edge cases
    • Targeted surveys to refine judgment on difficult categories

We also conducted training and testing sessions with annotators focused on:

  • Eliminating errors in high-complexity cases
  • Aligning the team on annotation logic and edge-case handling
  • Ensuring consistent interpretation of classification criteria

The Result

  • The model trained on our annotated data was successfully tested and deployed on the client’s platform. Internal testing involved evaluating model performance against randomly selected user messages
  • The initial testing phase showed promising results:
    • The model accurately blocked inappropriate or restricted content
    • Responses remained contextually appropriate across various scenarios

Similar Cases

  • Image
    Data Collection

    Image Data Collection for a Palm Recognition Task

    Collecting 20,000 palm photos sounds easy until you try it. We managed scale, verification, and logistics to deliver a clean dataset.

    Lean more
  • Image
    Image Annotation

    Image Segmentation for Retail Applications

    How do you segment every single object in a cluttered interior photo — 30+ classes per image? We designed a multi-step annotation pipeline to handle complexity without losing precision.

    Lean more
  • Image
    Text Labeling

    Sentiment Annotation for Brand Monitoring

    We built a scalable sentiment annotation pipeline that handles sarcasm, ambiguity, and domain-specific nuance — enabling smarter brand analysis and customer insight.

    Lean more
  • Image
    Video Annotation

    Surveillance Video Annotation for Entrance Monitoring

    If you want an algorithm to recognize violence, you cannot feed it polite data. We built 200 raw, high-intensity fight scenes from scratch in just two weeks, across real locations, with trained fighters and multi-angle 4K capture, creating the kind of high-stress visual data a surveillance model needs to perform beyond the lab.

    Lean more
  • Image
    Image Annotation

    License Plate Annotation for Vehicle Recognition System

    How do you annotate 100,000 license plates with dozens of nuances — from Arabic characters to regional codes — and still meet a two-week deadline?

    Lean more

Ready to get started?

Tell us what you need — we’ll reply within 24h with a free estimate

    What service are you looking for? *
    What service are you looking for?
    Data Labeling
    Data Collection
    Ready-made Datasets
    Human Moderation
    Medicine
    Other
    What's your budget range? *
    What's your budget range?
    < $1,000
    $1,000 – $5,000
    $5,000 – $10,000
    $10,000 – $50,000
    $50,000+
    Not sure yet
    Where did you hear about Unidata? *
    Where did you hear about Unidata?
    Head of Client Success
    Andrew
    Head of Client Success

    — I'll guide you through every step, from your first
    message to full project delivery

    Thank you for your
    message

    It has been successfully sent!

    We use cookies to enhance your experience, personalize content, ads, and analyze traffic. By clicking 'Accept All', you agree to our Cookie Policy.