---
title: "Review Criticality Index"
description: "Should I review this document carefully? Combines per-word density with delta and changed-anchor terms."
keywords: ["rci", "review criticality", "documentation review", "diff"]
---

**RCI** answers "Should I review this document carefully?". A small document can be review-critical if
it is dense with technical anchors. RCI combines a per-word **DensityScore** with a delta term and a
changed-links/artifacts term.

## Formula

```text
DensityScore = mehen-internal blend of:
    MCC per word
  + MDH volume per word
  + RepositoryGroundingScore
  + EvidenceCoverageScore
  + LinkReviewBurden per word
  + embedded code complexity per word

RCI = clamp01(
    0.65 · DensityScore
  + 0.20 · sat(abs(metric_delta_percent); 10, 60)
  + 0.15 · sat(changed_links_or_artifacts; 2, 20)
) · 100
```

## Bands

| RCI | Meaning |
|---|---|
| 0–25 | Low — skim is fine. |
| 26–50 | Normal review. |
| 51–75 | Careful review recommended. |
| 76–100 | High-risk change. |

## DMI × RCI × Filler matrix

| DMI | RCI | Filler Risk | Meaning |
|---|---|---|---|
| High | Low | Low | Long but easy and probably healthy. |
| High | Low | High | Easy to maintain but likely low-value filler. |
| Low | High | Low | Dense valuable doc; review carefully. |
| Low | High | High | Dangerous: hard to maintain *and* weakly grounded. |

This matrix is the canonical way to summarize a Markdown file in CI.

## References

- Bacchelli, A. & Bird, C. (2013). *Expectations, outcomes, and challenges of modern code review.*
  ICSE 2013 — empirical basis for prioritizing review attention by per-change density.
  [DOI](https://doi.org/10.1109/ICSE.2013.6606617) ·
  [Author copy](https://www.microsoft.com/en-us/research/publication/expectations-outcomes-and-challenges-of-modern-code-review/).
- Rigby, P. C. & Bird, C. (2013). *Convergent contemporary software peer review practices.*
  ESEC/FSE 2013 — supports the "review what changed" prioritization that RCI encodes.
  [DOI](https://doi.org/10.1145/2491411.2491444).

## See also

- [DMI](/metrics/markdown/dmi) — orthogonal "is it maintainable?" axis.
- [Filler / Lazy Risk](/metrics/markdown/filler-lazy-risk) — orthogonal "is it filler?" axis.
- [PR comment design](/guides/pr-comment-design) — RCI in the drill-down section.
