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GPT-5 Model Documentation

Overview

GPT-5, also referred to as gpt-5-thinking and gpt-5-main, is a high-capability language model developed by OpenAI. It is designed to excel in various domains, particularly in biology and chemistry, while addressing significant challenges in language understanding and generation.

Key Features

  • High Capability: Demonstrates advanced reasoning abilities, significantly reducing hallucination rates and improving instruction-following capabilities.
  • Safety Enhancements: Implements robust safety measures to mitigate risks associated with harmful content generation, including biological and chemical threats.
  • Real-time Adaptation: Utilizes a real-time router for model selection based on conversation context, improving response relevance and accuracy.

Problem-Solving Capabilities

GPT-5 addresses a variety of complex problems, including:

  • Answering diverse questions across multiple domains.
  • Handling intricate reasoning tasks and reducing the occurrence of hallucinations.
  • Enhancing performance in writing, coding, and urgent health-related inquiries.
  • Evaluating and mitigating risks associated with cyberoffensive challenges and biological threats.

Methodology

Training and Evaluation

  • Reinforcement Learning: Trained to reason through reinforcement learning, producing a long internal chain of thought before generating responses.
  • Evaluation Settings: Assessed through various benchmarks, including real-world software engineering tasks, cyber range exercises, and biological evaluations.

Key Contributions

  • Safe-completions: A mechanism to maximize helpfulness while adhering to safety constraints.
  • Post-training Adjustments: Focused on reducing sycophantic behavior through evaluated responses and assigned reward signals.
  • Red Teaming: Engaged expert evaluators to assess model safety and effectiveness, leading to improved robustness against harmful outputs.

Performance Metrics

GPT-5 has demonstrated significant improvements over its predecessors:

  • Hallucination Rate: A reduction to 0.4 for gpt-5-thinking, compared to 0.46 for OpenAI o3.
  • Factual Accuracy: 78% fewer responses with major factual errors compared to OpenAI o3.
  • Safety Perception: Perceived as safer 65% of the time compared to OpenAI o3.

Technical Components

Techniques and Modules

  • Real-time Router: Optimizes model selection based on user interactions.
  • Deception Mitigation: Reduces the model's tendency to generate deceptive responses.
  • Multilayered Defense Stack: A proactive system designed to prevent harmful content generation.

Data Requirements

  • Utilizes publicly available and third-party information, alongside user-generated data to enhance model training and performance.

Evaluation Results

GPT-5 has been evaluated across multiple dimensions, including:

  • HealthBench Performance: Outperforms previous models, achieving a score of 46.2 on hard health-related tasks.
  • Cybersecurity Challenges: Comparable performance in Capture the Flag and Cyber Range exercises.
  • Safety Metrics: High scores in not unsafe categories across various prompt types, indicating robust safety features.

Limitations and Future Directions

While GPT-5 shows significant advancements, it still faces challenges:

  • Emotional Distress Detection: Needs improvement in recognizing and responding to emotional distress in users.
  • Complex Problem Solving: Demonstrated weaknesses in solving hard challenges and certain scenarios during evaluation.

Conclusion

GPT-5 represents a significant step forward in language modeling, combining advanced reasoning capabilities with a strong focus on safety and accuracy. Its ongoing development and evaluation will continue to refine its capabilities and address existing limitations.

Sources

https://arxiv.org/abs/2601.03267v1