Your Knowledge Base

Recording Negative Evidence

How to record a search that found nothing on a person in KleioBase: the event type, the period searched and the notes, where each entry then appears, and how it travels in a GEDCOM export.

Last updated September 30, 2026

Searching a register and finding nothing is a real research result. It is what separates "I have not looked for their marriage" from "I read the Kalisz registers cover to cover and there is no marriage there". Those two statements look identical on a family tree, and they mean completely different things.

Negative evidence in KleioBase is where you record the second one. Each entry says what you looked for, over what period, and what you actually searched. This page covers how to record it in the app. For what the term means, see What is negative evidence?, and for what makes an empty search trustworthy, see How to Use Negative Evidence in Genealogy.

Before you start

Negative evidence is available on every plan, including the free Explorer plan. There is nothing to turn on.

One thing it interacts with, Expected records, is a Researcher-plan feature. Recording negative evidence works without it. See Plans & Billing for what each plan includes.

Adding an entry

  1. Open the person, click the pencil icon (Edit profile) and then More details.
  2. Choose Negative evidence in the left-hand list, the last section.
  3. Click + Add. A new row appears, defaulting to Marriage.
  4. Set Event type to the kind of record you looked for.
  5. Optionally set Period searched to the years your search covered.
  6. In the notes, write what you actually searched.
  7. Save, or Save & close.

Use the trash icon on a row to remove an entry.

Event type

You can record a search for any event GEDCOM recognises, individual or family: births, marriages, deaths, burials, census returns, baptisms, bar and bat mitzvahs, immigration and emigration, naturalisation, probate, wills, graduations, retirements, adoptions, engagements, annulments, divorces and more.

The one thing you cannot pick is the generic "Event", because "no unspecified event occurred" does not assert anything.

Period searched

The period is what makes the entry checkable later. "No marriage record" is a claim about all of history. "No marriage record between 1889 and 1900" is a claim someone can verify, extend, or disagree with.

Enter it the same way you would any date range: pick From - to or Between - and in the date-type dropdown and fill in both ends. Before and After work too if your search was open at one end. See Dates and Calendars for everything the date field can express.

The notes are the important part

An entry without notes records that you looked. An entry with notes records what you looked at, which is what makes it useful to you in two years and to anyone reading your research.

Write down the specific source and its limits. Compare:

  • "Searched for a marriage." Says almost nothing.
  • "Read the Kalisz Roman Catholic parish marriage register page by page, 1889-1900. The 1893 volume is water-damaged and roughly forty entries are unreadable." Says exactly how far your search reached and where it did not.

The second version tells your future self not to re-read the whole register, and to go straight to 1893 in a different source.

Two kinds of entry

With a period - "I searched here and did not find it". This is the common case. The event may still have happened; you have established it is not recorded in the source you searched, over the years you searched.

Without a period - "this never happened at all". Leave the period empty when you know the event genuinely did not occur, not merely that no record survives. A woman who never married has no marriage record anywhere, and that is a fact about her life rather than a limit of your search.

The distinction matters because it changes what the entry means to a reader, and it changes where the entry appears.

Where entries appear

Dated entries plot on the person's timeline under the Research overlay toggle, alongside research gaps and potential censuses. They sit at the start of the period searched, in the chronological place that explains a gap.

They render struck through and in a muted orange, so a search that found nothing can never be misread as something that happened. The same toggle that hides gap markers hides these.

An entry with no period does not appear on the timeline, because a claim about all of time has no single point to sit at. It still lives in the editor and still exports.

What an entry changes

Once you have established there is no marriage record for someone, Expected records stops prompting you to find one.

This applies to births, marriages, deaths and burials only. Census and military targets keep appearing, because not finding someone in the 1890 census says nothing about 1900.

The Research Companion reads your entries too. Attach a person to a conversation and it can see what you have already searched, so asking "where should I look next for her marriage?" gets an answer that starts from the registers you have ruled out instead of suggesting them back to you. It can read these entries but not write them; adding one is still something you do in the editor.

Your entries travel with your tree

Each entry is written into your GEDCOM export and read back on import. The two kinds of entry are written differently, because GEDCOM 7 treats them differently.

An entry without a period ("this never happened") uses GEDCOM 7's standard non-event structure, which any program that supports GEDCOM 7 understands:

1 NO MARR
2 NOTE Never married; named as a spinster in her 1932 will.

An entry with a period is a search result, and GEDCOM 7's NO would say more than you found: NO MARR with a date means "did not marry in those years", not "not in the register I read". So a dated entry is written as a KleioBase extension, declared in the file header, which KleioBase reads back in full:

1 _NOREC MARR
2 DATE FROM 1889 TO 1900
2 NOTE Read the Kalisz parish marriage register page by page.

Other programs may ignore extensions, so if you move your tree elsewhere, check how it handles them. If you import a file from another program that contains a dated NO, KleioBase keeps it as that program's stronger statement and writes it back out as NO.

One exception: if you tick Redact living people when exporting, negative evidence is left out for the people being redacted. What someone has searched for and not found about a living person is still information about that person, so redaction withholds it along with their dates and places. See Importing & Exporting for the rest of what redaction covers.

A worked example

You are researching Miriam, born 1888, who appears in a 1910 census as unmarried and never appears again. You want to know whether she married.

  1. You read the town's civil marriage register for 1904 to 1915, line by line, and find nothing.
  2. Open Miriam, Edit profile, More details, Negative evidence, + Add.
  3. Event type Marriage. Period From 1904 to 1915.
  4. Notes: "Read the civil marriage register for the town line by line, 1904-1915. Index not used; searched the pages themselves. No entry under any spelling of the surname."
  5. Save.

Her timeline now shows that search sitting between her 1904 and 1915 events, struck through, with the years attached. Expected records stops asking for a marriage. If you later find her married in a neighbouring town, the entry is still correct: the marriage is not in that register, which tells you something about where the family was.

Further reading

More in Your Knowledge Base

Still stuck? Email support@kleiobase.com or ask the Research Companion inside the app.

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