--- title: "MRI Score" description: "MRI Score is the Machine Relations Index metric for AI source authority. It reports how often AI answer engines cite each source domain as a source-segment citation rate, published only once a segment clears an evidence floor and graded into confidence tiers by how much evidence stands behind it." canonical: https://authoritytech.io/glossary/mri-score last-updated: 2026-07-09 --- # MRI Score MRI Score is the Machine Relations Index metric for AI source authority. It reports how often AI answer engines cite each source domain as a source-segment citation rate, published only once a segment clears an evidence floor and graded into confidence tiers by how much evidence stands behind it. Canonical URL: https://authoritytech.io/glossary/mri-score Category: metrics Published: 2026-07-09 MRI Score is the source-authority metric produced by the [Machine Relations Index](https://machinerelations.ai/index). It measures how often AI answer engines cite a root domain when responding to B2B buyer-intent questions. MRI Score is not a brand-visibility score, an SEO score, a backlink score, or a popularity score. It reports observed citation behavior: whether engines such as ChatGPT, Perplexity, Gemini, Claude, Google AI Mode, and Google AI Overviews actually select a domain as a cited source. AuthorityTech uses MRI Score as source-layer context for Machine Relations work. ## What MRI Score Measures The canonical definition, maintained at [machinerelations.ai](https://machinerelations.ai/glossary/mri-score): > The Machine Relations Index v2 reports source-segment citation rates — how often AI answer engines cite each source domain — published only once a segment clears the evidence floor of at least 10 observations across at least 7 distinct run dates, with each domain graded into confidence tiers A, B, C or collecting by how much evidence stands behind it. The unit of measurement is a source segment: one market category paired with one buyer question type. Within a segment, the citation rate is the share of observed answer runs in which an engine cited the domain. A segment publishes a rate only after it clears the evidence floor; below that line it is marked collecting rather than scored, so thin or early signal is never presented as settled authority. ## How MRI Score Is Modeled Every domain an answer engine cites is measured on equal terms. For each subject category paired with a buyer question type, the model counts how many observed answer runs cited a domain and divides by the total observed runs for that segment to produce a citation rate. Rates are published only for segments that have accumulated enough observations across enough separate days to be stable; thinner segments are shown as still collecting rather than scored. Domains are ranked within their source type and across the full measured universe, and each domain carries a confidence grade reflecting the volume of evidence behind its rate. ## Methodology Version The current standard is MRI Score v2.0, effective 2026-07-05. It superseded the earlier six-engine composite, MRI Score v1.1, which combined several weighted signals into a single number. v1 scores are not comparable to v2 citation rates; the two measure different things. The one-time [v1-to-v2 crosswalk](https://machinerelations.ai/index) is the transition receipt. Earlier writeups that describe MRI Score as a single weighted composite reflect the retired v1.1 methodology. ## MRI Score vs. AI Visibility Score MRI Score and [AI Visibility Score](/glossary/ai-visibility-score) measure different layers. MRI Score measures source-domain citation authority. AI Visibility Score measures a brand's presence inside AI-generated answers. A company can improve AI visibility by earning coverage, evidence, and entity clarity in the source domains that already carry strong MRI Scores. ## Public Boundary The public dataset reports citation rates, rankings, and evidence counts. It excludes internal query identifiers, raw cited URLs, and answer-engine provider payloads. ## Canonical Reference MRI Score is defined and maintained as a public standard at [machinerelations.ai/glossary/mri-score](https://machinerelations.ai/glossary/mri-score), the category-defining asset for Machine Relations and the Machine Relations Index. Machine Relations was coined by AuthorityTech founder Jaxon Parrott. AuthorityTech applies MRI Score as a practitioner and links to the canonical definition rather than restating the methodology. ## Related Terms - machine-relations-index - machine-relations - ai-visibility-score - citation-share - earned-authority ## Sources - https://machinerelations.ai/glossary/mri-score - https://machinerelations.ai/glossary/machine-relations-index - https://machinerelations.ai/index - https://machinerelations.ai/machine-relations-index.md - https://machinerelations.ai/research/machine-relations-index-methodology - https://machinerelations.ai/research/source-type-authority-ai-search-mri-2026 - https://machinerelations.ai/data/machine-relations-index.json - https://authoritytech.io/glossary/source-authority - https://authoritytech.io/glossary/ai-brand-authority ## Links - [Glossary Index](https://authoritytech.io/glossary.md) - [Home](https://authoritytech.io/index.md)