{
  "id": "text-degeneration",
  "code": "PTL-0175",
  "term": "Text Degeneration",
  "aliases": [
    "neural text degeneration",
    "repetition",
    "repetition loops"
  ],
  "category": "failure-modes",
  "definition": "Text degeneration is the tendency of language models, especially under greedy or beam-search decoding, to produce bland, repetitive, or looping text, such as the same phrase repeated over and over.",
  "description": "Maximizing likelihood at each step favors safe, high-probability continuations that reinforce themselves once repetition starts. Sampling methods such as top-p and top-k, repetition or frequency penalties, and modern training largely mitigate it, but loops still appear in long generations and agent traces.",
  "example": null,
  "broader": [],
  "narrower": [],
  "related": [
    "greedy-decoding",
    "top-p-sampling",
    "top-k-sampling",
    "temperature"
  ],
  "introduced": 2019,
  "added": "2026-10-10",
  "sources": [
    {
      "title": "The Curious Case of Neural Text Degeneration",
      "authors": "Holtzman et al.",
      "year": 2019,
      "url": "https://arxiv.org/abs/1904.09751"
    }
  ],
  "url": "https://protologue.com/t/text-degeneration/",
  "citation": "Protologue. (2026). Text Degeneration. In Protologue: A Taxonomy of Prompting and LLM Techniques (v1.4.0, PTL-0175). https://protologue.com/t/text-degeneration/"
}