Table 2. LLMs evaluated in phase 1.
| Model | Developer | Version/model ID | Access date | Access method |
|---|---|---|---|---|
| ChatGPT | OpenAI | GPT-5.4 | April 2026 | Web interface (chat.openai.com) |
| Gemini | Gemini 3.1 Pro | April 2026 | Web interface (gemini.google.com) | |
| DeepSeek | DeepSeek AI | DeepSeek-V4 (V4-Pro) | April 2026 | Web interface (chat.deepseek.com) |
| Perplexity | Perplexity AI | Perplexity Pro (multi-model synthesis) | April 2026 | Web interface (perplexity.ai) |
Model versions reflect the publicly available default models at the time of access. Given the continuous deployment nature of these platforms, exact underlying model versions are subject to change without notice. AI, artificial intelligence; LLM, large language model.