Is GPT-o1 Content Detectable?

OpenAI released a new series of AI models designed to spend more time thinking before they respond — GPT-o1-preview. In their release, OpenAI describes that it can reason through complex tasks and solve harder problems than previous models in science, coding, and math.

As the new model was trained with reasoning traces and can spend time considering before it answers, in some domains, this has led to greater performance than before. In order to maintain the authenticity and integrity of written content available online, it is necessary to have a greater AI content detector as well.

This brief study looks at 1000 GPT-o1-preview generated text results to find out whether the Originality.ai AI Detector can detect GPT-o1-preview.

TL;DR — Is GPT-o1 AI-Generated Content Detectable?

• Yes — GPT-o1 generated-text is detectable with a high degree of accuracy across the Originality.ai AI detection models.
• Results Overview — 3.0.0 Turbo demonstrated 93.47% accuracy, 1.0.0 Lite had 91.66% accuracy, and 2.0.1 Standard had 94.47% accuracy.
• Originality.ai showed strong performance in contrast to GPTZero — While GPTZero struggled to detect 'rewrite human-written text' samples, Originality.ai continued to show robust AI detection capabilities.
• Accuracy Will Quickly Improve — With the release of Turbo 3.0.1 in October 2024, 3.0.1 is now demonstrating 98% accuracy in detecting GPT-o1 preview text. As with most model releases by OpenAI, Originality.ai will quickly work to improve our accuracy to 99%+. 

Try the Originality.ai AI Detector. Then, learn about AI content detection accuracy and Originality’s strong performance in a meta-analysis of eight third-party studies. 

Dataset

To evaluate the detectability of GPT-o1, we prepared a dataset of 1000 GPT-o1-preview generated text samples.

The Method: gathering AI-generated text data

For AI-text generation, we used GPT-o1-preview based on three approaches:

1. Rewrite prompts: The first approach generated content by providing the model with a custom prompt and articles (probably generated by LLMs) as a reference to rewrite from (450 Samples).
2. Rewrite human-written text: The second approach involved generating content with the aim of finding out whether AI rewrites of human-written text could bypass AI detection. The samples for this approach were fetched from an open-source dataset (325 Samples).
   1. One-Class Learning for AI-Generated Essay Detection
      1. Paper: https://www.mdpi.com/2076-3417/13/13/7901
      2. Dataset: https://github.com/rcorizzo/one-class-essay-detection
3. Write articles from scratch: The third approach, generated articles from scratch based on topics ranging from fiction to nonfiction, such as history, medicine, mental health, content marketing, social media, literature, robots, the future, etc. (225 Samples).

Evaluation

To evaluate the efficacy, we used the Open Source AI Detection Efficacy tool that we released:

• AI Detector Used in this Study
• AI Detector Efficacy Testing Article
• Open Source AI Detection Efficacy Testing Tool

A brief overview of the Originality.ai AI detection models

Originality.ai has three models, 3.0.0 Turbo,  2.0.1 Standard, and 1.0.0 Lite, for AI text detection.

• 3.0.0 Turbo — If your risk tolerance for AI is ZERO! It is designed to identify any use of AI, even light AI.
• 2.0.1 Standard — A balanced model that is a great option if you are okay with slight use of AI (i.e., AI editing).
• 1.0.0 Lite — If you permit light AI editing (such as Grammarly’s spelling or grammar suggestions).

For additional information on each of these models, check out our AI detector and read our AI detection accuracy guide.

Evaluating the AI detection models

The open-source testing tool returns a variety of metrics for each detector you test, each of which reports on a different aspect of that detector’s performance, including:

• Sensitivity (True Positive Rate): The percentage of time the detector identifies AI correctly.
• Specificity (True Negative Rate): The percentage of time the detector identifies human-written content correctly.
• Accuracy: The percentage of the detector’s predictions that were correct.
• F1: The harmonic mean of Specificity and Precision, often used as an agglomerating metric when ranking the performance of multiple detectors.

For a detailed discussion of these metrics, what they mean, how they're calculated, and why we chose them, check out our blog post on AI detector evaluation. For a succinct snapshot, the confusion matrix is an excellent representation of a model's performance.

Below is an evaluation of all these models on the above dataset. 

Confusion Matrix

Results of the Evaluation :

For this smaller test to identify the ability of Originality.ai’s AI detector to detect GPT-o1-preview content, we reviewed the True Positive Rate or the percentage (%) of time that the model correctly identified AI text as AI out of 1000 samples of GPT-o1-preview content. 

1.0.0 Lite:

• Recall (True Positive Rate) = 91.66%

2.0.1 Standard:

• Recall (True Positive Rate) = 94.47%

3.0.0 Turbo:

• Recall (True Positive Rate) = 93.47%

Can GPTZero Detect GPT-o1?

To compare the efficacy of AI detectors, we also evaluated the dataset on the GPTZero AI detector. We've included the results of this performance below.

GPTZero Performance:

Additionally, we also ran the tool — GPTZero on the same dataset and here is its performance:

• Recall (True Positive Rate) = 56.88%

Comparison Table: 

Based on the results, we were able to see that GPTZero significantly struggled with detecting Rewrite human-written text, whereas Originality continued to demonstrate a strong performance.

Final Thoughts

Overall, Originality.ai continues to demonstrate an outstanding capability to identify AI-generated content, including the latest releases of AI models such as OpenAI’s GPT-o1, GPT-4o and GPT-4o-mini. 

Each of Originality.ai’s AI detection models detected GPT-o1 with a high degree of accuracy from 3.0.0 Turbo with 93.47% accuracy to 2.0.1 Standard with 94.47% accuracy, and 1.0.0 Lite with 91.66% accuracy. With the latest updates to our AI detection models, Turbo 3.0.1 can now detect GPT-o1-preview with 98% accuracy. Our machine learning engineers are continuing to improve our accuracy to 99%+, as with most new models released by OpenAI.