Most family trees record what was found. The searches that came back empty leave no trace at all, which is why the same registers get read twice and why a question nobody has investigated looks identical to one that has been settled.
Negative evidence is the method for using those empty searches.
The silence has to be meaningful
The key word in the definition is should.
A man appears in a county tax list every year from 1840 to 1849, then disappears from it while the list continues to be kept and continues to name his neighbours. He is not in the local burial register either. The list should contain him and does not. That absence is an argument: he probably left around 1850, and you now have both a date range and a direction to search.
Contrast that with searching a parish register whose volumes for the years you need were destroyed in a fire. You also found nothing, but here the silence is a fact about the archive rather than about your ancestor, and no conclusion follows from it.
Negative evidence versus negative findings
The two terms are often used interchangeably, but they mean different things.
| What it is | What it gives you | |
|---|---|---|
| Negative finding | A search that returned no result | A research fact to log |
| Negative evidence | An inference drawn from a meaningful silence | An argument to test |
A negative finding is always worth writing down. It becomes negative evidence only when you can say why the record should have been there.
The five questions that decide whether an empty search is trustworthy, with a worked example from first search to conclusion, are in how to use negative evidence in genealogy.
What it is used for
Establishing a date range. Someone present in one source and absent from the next gives you a window for whatever happened between them.
Eliminating a place. If a complete death register for a town shows no entry across the years someone could have died there, they died somewhere else.
Resolving a conflict. When two records disagree, the absence of a third can tip the argument.
Establishing a non-event. Sometimes the conclusion is that the thing never happened: a woman who never married, a couple who never divorced. That is a fact about the person's life, and it is recorded differently from a search result.
How to record it
Each entry is a short note containing what you looked for, the specific source, the span you covered, how you searched it (indexed or page by page, which spelling variants), and anything that limited the search.
"Searched for a marriage, nothing found" tells a later reader almost nothing. "Read the Kalisz parish marriage register page by page, 1889 to 1900, checking four spellings of the surname; the 1893 volume is water damaged and roughly forty entries are unreadable" is a finding, and it tells you exactly what to do next.
Historically this lived in a research log kept apart from the tree, which is why it so often went missing. GEDCOM 7 can now carry the conclusion in the file itself, with its NO structure for an event that did not happen. It has no standard structure for the search log behind it, so how a program exports "searched here, found nothing" is worth checking before you rely on it.
In KleioBase, negative evidence is recorded on the person it concerns rather than in a separate log. Dated entries appear on that person's timeline in the chronological place that explains the gap, struck through so they cannot be mistaken for something that happened, and they stop the app suggesting you look for a record you have already searched for.
Frequently asked questions
- What is the difference between negative evidence and a negative search result?
- A negative search result, also called a negative finding, is what happened when you looked. You searched the register and there was no entry. It is a fact about your research. Negative evidence is what you can conclude from that silence, given what you know about the source. Every piece of negative evidence begins as a negative finding, but a finding only becomes evidence when the source was complete, covered the right people and place, and would have recorded the event if it had happened.
- Can negative evidence prove something on its own?
- No. Elizabeth Shown Mills, whose Evidence Explained is the standard reference, holds that a negative must be developed into a positive through further research and supporting evidence before the inference is valid. "He is missing from the tax list" is a finding. "He is missing from the tax list, he appears in a neighbouring county two years later, and his land here was sold in between" is a conclusion.
- Why should I record searches that found nothing?
- The first element of the Genealogical Proof Standard is reasonably exhaustive research, and you cannot demonstrate you covered ground without a record of where you looked. Without a record you will repeat the same fruitless search years later and feel just as uncertain. Anyone continuing your research can only extend work whose boundaries they can see.
- What makes a negative search trustworthy?
- That the source covers the years and the place, that it covers these people at all (a Catholic parish register will not record a Jewish marriage), that you read the pages rather than an index, that you allowed for spelling variants, and that the event would have been registered in the first place. A negative that fails one of these is still worth recording, along with the reason it is weak.
- How do I record negative evidence in a family tree file?
- Partly. GEDCOM 7 has a non-event structure, "1 NO MARR", that states an event did not happen. With a "2 DATE" period it means the event did not happen within that span; without one, that it never happened at all. The specification says nothing under it may narrow that claim, so it suits a conclusion you have reasoned to, not a raw "not found in this register" finding. GEDCOM 7 has no standard structure for a search result on its own; KleioBase exports dated searches as a documented extension so they are not overstated.
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