comet-ml--opik/apps/opik-documentation/documentation/fern/docs/evaluation/metrics/summarization_coherence.mdx

---
description: Rate how readable and well-structured a summary is with SummarizationCoherenceJudge
headline: Summarization coherence | Opik Documentation
og:description: Evaluate summary clarity and structure with Opik's Summarization Coherence
  Judge, scoring readability from 0.0 to 1.0.
og:site_name: Opik Documentation
og:title: Summarization Coherence Metric - Opik
title: Summarization coherence
canonical-url: https://www.comet.com/docs/opik/evaluation/metrics/summarization_coherence
---

# Summarization Coherence Judge

`SummarizationCoherenceJudge` evaluates the writing quality of a summary: structure, clarity, and logical flow. It complements `SummarizationConsistencyJudge` by focusing on how the summary reads rather than whether it is factual, returning a 0.0–1.0 score derived from a raw 0–10 judgement.

```python title="Improving summary readability"
from opik.evaluation.metrics import SummarizationCoherenceJudge

metric = SummarizationCoherenceJudge()

score = metric.score(
    output="""SUMMARY: First, the product launched. Revenue grew. Margins fell. Next steps TBD.""",
)

print(score.value)   # 0.0–1.0 after normalisation
print(score.reason)
```

## Inputs

| Argument | Type | Required | Description |
| --- | --- | --- | --- |
| `output` | `str` | **Yes** | Summary text to evaluate. |
| `input` | `str` | Optional | Original document/talk track for additional context (not required). |

## Configuration

| Parameter | Default | Notes |
| --- | --- | --- |
| `model` | `gpt-5-nano` | Upgrade when assessing long-form or domain-specific summaries. |
| `temperature` | `0.0` | Raise slightly (≤0.3) to expose diverse stylistic critiques. |
| `track` | `True` | Toggle off to skip logging. |
| `project_name` | `None` | Override when tracking across projects. |

Pair this judge with `SummarizationConsistencyJudge` to ensure summaries are both factual and easy to skim. The evaluator returns a 0–10 integer that Opik normalises to 0–1.