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AI図鑑

構造化出力

決められた schema どおりの JSON を出させる

データとドキュメント初級 #39
入力テキスト表

本ページの本文は英語で提供されています。タイトルと導入は日本語化されています。

この能力とは何か

Takes natural language plus a target structure — field names, types, required flags — and outputs text that strictly conforms, such as JSON, XML or a table. Unlike information extraction the structure is supplied by the caller rather than inferred from the text; unlike tool use it produces the data itself, not a request to invoke some interface.

技術的にどう実現するか

The basic approach puts the schema and examples in the prompt and asks the model to fill them; more reliable is constrained decoding, which at each step allows only tokens that keep the structure valid, ruling out syntax errors during generation. Fine-tuning on many text-to-structure pairs familiarises the model with common field naming and type conventions. Large schemas can be split across several calls or filled in layers.

代表的な製品

5

関連する組織

代表的な用途

  • Converting natural language into API payloads
  • Auto-filling forms and order fields
  • Data cleaning and normalisation pipelines
  • Passing structured messages between agents

どう評価するか

Schema validity rate
Share of outputs that parse and satisfy the schema
Field exact match
Share of field values matching the reference
Value-level F1
Scores elements in lists and nested structures

限界と難しさ

  • With many fields or long enums it drops fields, picks the wrong value or invents new ones
  • Deep nesting and complex types such as unions or nullable arrays produce type errors
  • Tight format constraints squeeze reasoning, and the same model reasons less well under them

背景にある概念