Human vs. Machine Deception: Distinguishing AI-Generated and Human-Written Fake News Using Ensemble Learning
Organizations: School of Data Science and Analytics, Kennesaw State University, Kennesaw, GA · Department of Computer Science, Kennesaw State University, Kennesaw, GA · Department of Mathematics, Kennesaw State University, Kennesaw, GA
Abstract
The rapid adoption of large language models has introduced a new class of AI-generated fake news that coexists with traditional human-written misinformation, raising important questions about how these two forms of deceptive content differ and how reliably they can be distinguished. This study examines linguistic, structural, and emotional differences between human-written and AI-generated fake news and evaluates machine learning and ensemble-based methods for distinguishing these content types. A document-level feature representation is constructed using sentence structure, lexical diversity, punctuation patterns, readability indices, and emotion-based features capturing affective dimensions such as fear, anger, joy, sadness, trust, and anticipation. Multiple classification models, including logistic regression, random forest, support vector machines, extreme gradient boosting, and a neural network, are applied alongside an ensemble framework that aggregates predictions across models. Model performance is assessed using accuracy and area under the receiver operating characteristic curve. The results show strong and consistent classification performance, with readability-based features emerging as the most informative predictors and AI-generated text exhibiting more uniform stylistic patterns. Ensemble learning provides modest but consistent improvements over individual models. These findings indicate that stylistic and structural properties of text provide a robust basis for distinguishing AI-generated misinformation from human-written fake news.
Figures & tables
| Source | Excerpt |
|---|---|
| Human-written | “Reuters reported that Nancy Pelosi bought 10 million shares of cannabis stock. On Oct. 6, President Joe Biden said he would pardon all people convicted of simple marijuana possession offenses under federal law and directed Cabinet members to review how the drug is classified. Later that day, a claim started to spread on social media that House Speaker Nancy Pelosi had bought millions of shares of cannabis stock before Biden’s announcement.” |
| AI-generated | “Following President Joe Biden’s announcement on Oct. 6 that he would pardon all federal convictions for simple marijuana possession and direct a review of the drug’s federal classification, a viral claim surfaced on social media asserting that House Speaker Nancy Pelosi had purchased millions of shares of cannabis stock. An Oct. 7 Instagram post stated, ‘Breaking: Nancy Pelosi purchased 10,000,000 shares of $WEED 4 days ago,’ attributing the claim to Reuters.” |
| Model | Parameter(s) tuned | Candidate values | Most frequently selected setting |
|---|---|---|---|
| Logistic regression | None | - | - |
| Random forest | 2, 3, 7 | (9/10 outer splits) | |
| SVM (radial) | , | : 0.01, 0.05, 0.10; : 0.5, 1, 2, 4 | , (9/10) |
| XGBoost | rounds, depth, learning rate | rounds: 100, 200; depth: 2, 4; : 0.05, 0.10 | No single dominant setting |
| Neural network | hidden units, weight decay | units: 5, 10, 15; decay: 0, 0.001, 0.01 | 15 units, decay 0.01 (9/10) |
| Model | Accuracy | AUC | Precision | Recall | Specificity | F1 |
|---|---|---|---|---|---|---|
| Ensemble | 0.955 (0.014) | 0.993 (0.003) | 0.954 (0.020) | 0.956 (0.022) | 0.954 (0.021) | 0.955 (0.014) |
| Logistic | 0.953 (0.014) | 0.991 (0.005) | 0.951 (0.020) | 0.956 (0.022) | 0.951 (0.021) | 0.953 (0.014) |
| NN | 0.934 (0.027) | 0.953 (0.030) | 0.933 (0.032) | 0.935 (0.041) | 0.932 (0.035) | 0.934 (0.029) |
| RF | 0.947 (0.016) | 0.990 (0.004) | 0.957 (0.018) | 0.937 (0.025) | 0.957 (0.019) | 0.947 (0.016) |
| SVM | 0.948 (0.015) | 0.991 (0.004) | 0.944 (0.018) | 0.953 (0.025) | 0.943 (0.020) | 0.948 (0.015) |
| XGBoost | 0.953 (0.014) | 0.991 (0.004) | 0.959 (0.018) | 0.947 (0.022) | 0.959 (0.019) | 0.953 (0.014) |