Work out why a search found nothing

The search did not find what I needed. **Work out why, and what to do.**

1. **Which of these it is:**
   - **It exists but my wording missed it** — ***the terms the field actually uses differ from mine.* **Say what they are likely to be**
   - **It exists but is not on the open web** — ***behind a login, in a paid database, in a document nobody posted***
   - **It exists offline** — ***a registry, an office, a person.* **Say which**
   - **Nobody has measured or published it** — ***say so plainly***
   - **The question cannot be answered in this form** — ***it is a judgment, or it depends on something unstated***
2. ***If the tool produced something anyway, check it against the question*** — **a fluent answer to a question with no answer is the outcome to watch for. Say whether that is what happened**
3. **Alternative routes:** ***different terms / a related measurable thing / whoever would have to know / the nearest question that does have an answer***
4. ***What a good-enough substitute would be*** — **and what it costs to use it instead**

**Then:** ***whether to keep looking or to proceed without it.* **Say which, and what proceeding without it means for my conclusion.**

⚠️ ***Do not fill the gap from your own knowledge. Do not offer the nearest available answer as if it were the one I asked for.*** **"This does not appear to be published" is a complete and useful answer.**