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Method status: NRLC uses this operational convention to make repeated observations comparable. It is not presented as an industry-standard definition.

Use three observable states per prompt: cited (URL or domain attributed as a source), mentioned (brand name only), or absent. Under the NRLC measurement convention, citation rate = C / P. C is the number of eligible prompts with a qualifying citation; P is the total number of eligible prompts evaluated. Every reported rate must identify the engine, prompt set, denominator, and observation window.

Search Console’s Performance report can show Google Search query and page associations. It does not directly report ChatGPT or Perplexity citation share. Track those engines with a prompt log. See tracking AI citations.

Methodology

  1. Freeze the prompt set: Assign the prompt list a version and do not add, remove, or rewrite prompts during the observation window.
  2. Name the environment: Record the engine, interface or mode, account state when relevant, and run date.
  3. Classify each answer: Record a qualifying URL or domain citation, entity mention without citation, competitor citation, or no observed source.
  4. Apply eligibility rules: Exclude failed requests and unusable responses before fixing P, then preserve the exclusion log.
  5. Calculate and report: Calculate C / P and report C, P, engine, prompt-set version, and observation window together.

Unit of observation

One observation is one eligible prompt response from one named engine and interface on one recorded run date. Store the prompt-set version and the response evidence with the classification. Do not combine engines into one rate unless each engine’s denominator and result remain separately visible.

Limitations

This method measures observed outputs, not private model reasoning. Results can vary by engine, interface, prompt wording, account state, and time. A citation occurrence does not prove that a source caused an answer, produced a click, or generated revenue. NRLC has not published a worked citation-rate example because there is not yet an observation log with a prompt count, engine, dates, citation count, or citation rate.

External scope reference