Methodology, honestly
The Index publishes measurements, never judgements. Here is exactly how the numbers are made — and where they stop.
What we measure
Every week we ask four AI assistants — ChatGPT, Claude, Gemini and Perplexity — a fixed basket of 80 real diner questions about Edinburgh. We record every restaurant named in every answer, and its position. A restaurant's share of voice is the percentage of all answers that name it. That's the whole method: same questions, same models, same way, every week.
How a run works
- 80 prompts spanning cuisine, neighbourhood, occasion, budget and visitor questions — phrased the way people actually type them.
- 4 models × 80 questions = 320 answers per week, each stored in full.
- Names are extracted from every answer and matched to a canonical list of Edinburgh restaurants.
- We keep every raw answer, so week-over-week movement is auditable.
What “share of voice” means (and doesn't)
Share of voice is the share of relevant answers that name a restaurant — not a “rank”. Any single AI chat can differ from the next, so we never report a one-off position. We report the pattern across hundreds of answers, and how it moves over time.
The honest caveats
- API answers are directional. We query each model's public API with no personalisation. The consumer apps add account history and live web search, so an individual chat you run may differ. We publish this prominently because it's true.
- Answers vary run to run. That's why the Index is a weekly average across many prompts, and why movement matters more than any single number.
- Perplexity is search-grounded natively; the other three run un-grounded in this version. A “live web” column is on the roadmap.
The restaurant list
Our canonical list is built from Google Places — Edinburgh venues with 25+ reviews — then cleaned by hand each week (chains and non-restaurants removed, closures noted). Currently tracking 925 restaurants. When an AI recommends a place that has closed, we leave it off the list and note it — that's a finding, not an error.
No pay-to-appear
No restaurant can pay to appear in the Index, or to move within it — including our own audit clients. The measurement and the paid work are kept strictly separate.
Corrections
Spotted something wrong — a closed venue, a mismatched name, a restaurant we've missed? Email hello@almanach.scot and we'll fix it in the next run. The full dataset and methodology are available to journalists on request.