# Diffraction glossary

> Definitions of aberration, UI review, and product experience review. How Diffraction names product experience failures on UI-affecting GitHub PRs for web apps.

Canonical: https://www.diffraction.sh/glossary

## TL;DR

Three terms we use on purpose: UI review and product experience review name the practice; aberration names a verified finding.

Diffraction is not visual testing and not a source-only PR bot. Longer reads: https://diffraction.sh/ui-review and https://diffraction.sh/ui-review-vs-visual-testing

## Quotable one-liners



## Aberration

An aberration is a verified product-experience failure found while reviewing a running UI, backed by evidence a reviewer can replay or inspect.

In Diffraction language, aberrations are the unit of finding for UI review: concrete, evidenced, and tied to what a user would hit after a change.

See also: /glossary#ui-review, /glossary#product-experience-review, https://diffraction.sh/blog/three-checkboxes-almost-billion-dollars

## UI review

UI review is the practice of evaluating a UI-affecting change by experiencing the running product, especially on GitHub PRs for web apps, rather than by source reading or screenshot comparison alone.

UI review asks whether the product still works as a product: flows, defaults, states, and outcomes. Full explainer: https://diffraction.sh/ui-review

## Product experience review

Product experience review is UI review framed around whether real user journeys still succeed after a change: from first intent through completion, including errors and edge states.

Compare adjacent categories: https://diffraction.sh/ui-review-vs-visual-testing

## How these terms fit together

Practice: UI review / product experience review

Finding: aberration

Wedge: UI‑affecting GitHub PRs on web apps

Tagline: See the full spectrum of every diff.

Thesis: source correctness ≠ product correctness. Examples: https://diffraction.sh/blog/three-checkboxes-almost-billion-dollars, https://diffraction.sh/blog/six-people-national-signup-flow, https://diffraction.sh/blog/button-costing-300-million-a-year

## Soft product bridge

Diffraction is designed to surface verified aberrations with evidence and will, when live, support agent‑assisted UI review. Explore our projects on GitHub or email hello@diffraction.sh.

Role-specific framing: https://diffraction.sh/for/executives, https://diffraction.sh/for/designers-and-qa, https://diffraction.sh/for/engineers, https://diffraction.sh/for/engineering-leads