Ooooops…
The Legal Genealogist had an absolute ball last night giving a webinar for the Board for Certification of Genealogists, through Legacy Family Tree Webinars, on negative evidence.
It’s available online right now and for a few days will be free to review; afterwards, it’ll still be available for a small fee.
Now…
It’s true that negative evidence can be a tough topic, because even experienced genealogists can get confused about the exact distinction between direct, indirect and negative evidence in a particular situation.
Direct evidence, of course, is information that appears to answer a research question by itself.1 The example I used was from the 1850 U.S. census of Yancey County, North Carolina, with the research question of “what did Charles Baker do for a living?” The census reports his occupation as High Sheriff.2 That surely gives us the answer, by itself, and so it’s direct evidence.
But if the research question is “where was the Baker family living when Rebecca was born?”, we have a different situation. The census does tell us she was born in North Carolina,3 so surely that’s where her mother was at that moment — but it doesn’t tell us that’s where the family was living at the time. They could have been just passing through, or visiting with relatives or friends.
So we’d need to combine the birthplace with other evidence of residence to answer the question and that — by definition — makes it indirect evidence: a bit of information that has to be combined with other bits to answer the question.4
Negative evidence is another beastie: it’s a “type of evidence arising from an absence of a situation or information in extant records where that information might be expected.”5 In the words of the Sherlock Holmes story, it’s the dog that didn’t bark — when it should have barked — if what we thought was true was in fact true.6
Sometimes we get confused when we search for something — say, a particular person in a census — and we can’t find him, so we think that’s negative evidence. Nope. That’s just a negative search — we don’t have any basis yet for drawing an inference about what it means that we couldn’t find him. Maybe his entry was misindexed. Maybe the census taker skipped over that household. We just don’t know — and we don’t have a basis for speculating.
And sometimes — sigh — we get confused and think that evidence that negatives a proposition — that tends to disprove it — is negative evidence.
As — sigh — I did when one question came up at the end in the Q&A.
The question was whether DNA results could be negative evidence, and, in my answer, the example I used of a case that could be negative evidence… isn’t.
The example I used was a YDNA test. My Shew line from North Carolina against another Shew-Schuh line from Virginia. We had every reason to believe, based on the paper trail, that the Philip who disappeared from the records of Virginia right around the time that my Philip appeared in the records of North Carolina was one and the same Philip.
But YDNA testing thoroughly disproved that working hypothesis. Looking at just the very top level YDNA results — the haplogroup, or which branch of the male human family tree the test takers are sitting on7 — it’s not so: the Virginia line has a haplogroup of R, and my Shew line has a haplogroup of I — and you can’t have two lines descending from the same common male ancestor with two different haplogroups.
That’s not negative evidence.
It does in fact directly answer the research question: “Are the two Shew lines related through the direct paternal line?” The dog did bark — we got an answer to our research question. And the fact that the answer is in the negative (“no, they’re not”) doesn’t change it from direct evidence to negative evidence.
There may be situations where, perhaps, DNA evidence might be put in the negative evidence category. If so, however, it’s not going to be in any case where the DNA test merely disproves a research theory. Any time a test can directly show a relationship (“yes, two people are related”) or debunk a theorized relationship (“no, two people aren’t related, at least not in this way”), it’s direct evidence — even when the answer is no.
SOURCES
- See Board for Certification of Genealogists, Genealogy Standards (Nashville, Tennessee : Ancestry, 2014), 66. ↩
- 1850 U.S. census, Yancey County, North Carolina, population schedule, p. 450(A) (stamped), dwelling 975, family 967, Charles Baker; digital image, Ancestry.com (http://www.ancestry.com : accessed 4 Dec 2016); citing National Archive microfilm publication M432, roll 407. ↩
- Ibid., Rebecca A. E. Baker. ↩
- See Board for Certification of Genealogists, Genealogy Standards, at 70. ↩
- Ibid., at 71. ↩
- See A. Conan Doyle, “The Adventure of Silver Blaze,” Strand Magazine (July-December 1892) IV: 645; digital images, Google Books (http://books.google.com : accessed 4 Dec 2016). ↩
- ISOGG Wiki (http://www.isogg.org/wiki), “Haplogroup,” rev. 4 Oct 2016. ↩
As you deftly pointed out several times, the label you attach to a piece of evidence is determined by the research question being asked rather than the content of the evidence alone. Thoroughly enjoyed the mental calisthenics.
Glad you enjoyed it, Brian, and hope it helps!
I tell you one thing cousin, you had ol Stan’s head-a-spinnin on this one.
Just watch out for the “Beware of dogs!” sign! 🙂
Judy, I was an attendee at your webinar yesterday re negative evidence. I am still trying to wrap my brain around the concept. Would the following scenario be considered negative evidence. The question is when did Elizabeth Archer Hart daughter of Stephen Archer die? The evidence from the will of Stephen Archer names Elizabeth. Will written in 1838. The probate of the estate in 1846 does not list Elizabeth as an heir. Would this information which infers Elizabeth died before 1846 be considered negative evidence? Thanks
Yes. She was in document A and is not in document B, so there was a dog and it should have barked. In terms of the reasonableness of drawing the inference, there are some caveats, of course. For example, fathers often dowered their daughters when they married, and those gifts were often considered advancements. So you’d need to know whether the law of that jurisdiction would have counted Elizabeth out because she’d already gotten her share. And if she married in the interim, is her husband named in the probate (in the right or place of the wife)? Those are just two of the scenarios I can think of that would undermine the reliability of this as negative evidence.
This example of “direct evidence” may need a name of its own: I had built a very strong hypothesis based on several forms of evidence, even including X-DNA. Before declaring it fact, I always try to disprove it. Oops! the woman I presumed was the mother of a child born in July had had a stillborn baby the previous October. The only evidence of that was found in a cemetery record of a plot belonging to a distant family member. The chance that it could have remained a secret is very high, and my “fact” would have lived on forever.
That’s not absolutely impossible — it’s nine months from stillbirth to live birth. Unlikely, yes. But not impossible.
While the average preganacy lasts nine months, we all know that average includes some babies who are reluctant to leave the womb, and others who can’t wait to see the outside world. Wouldn’t it be necessary in this case to find an alternate explanation for the positive DNA evidence before the possibility the same woman was the mother of both children can be discarded?
With autosomal DNA (and X-DNA as well), there are a lot of alternative explanations possible. My point was that the time frame alone doesn’t make this an impossibility.
I’ve got an example of a parcel of negative evidence for one question and indirect evidence in the negative for my primary question. Trying to prove a circa 1850-1860 likely adoption of a direct ancestor. There is a candidate child (right age, right first name and middle initial) one house over on the 1850 census, listed as a pauper. Under the poor laws of the time and place, the town of residence was responsible for paupers. Lo and behold, there is exactly one family in town of that name according to the 1850 census – with no adult males or property. They are out of town by the 1860 census. I search for them. I found about a dozen records with some of the family members in other times and places. The child of that name is never with them. These records on that family are negative evidence for the question “Did that child return to his birth family?” and thus indirect evidence for the question “Is that child my great-great-grandfather?”
That certainly might work, depending…!
Great webinar. Hope everyone takes the time to listen in while it is still available for replay.
Great webinar – thank you. I learned such a lot and you explained the concept very clearly with excellent examples. I also appreciate the gracious way in which you admitted your error regarding the DNA – incorporating DNA evidence is a steep learning curve and so it was actually reassuring to see that even the experts get caught occasionally 😉
Merry Christmas
Thanks for the kind words. And a very Merry Christmas to you and yours as well.
I watched the webinar during the holiday week and enjoyed it. I do have a question regarding to whether I have done enough regarding negative evidence.
The question is “Where was William Henry Turner born?” All the records I have match regarding birth date but there is conflicting evidence regarding birth place. The locations in question are Newmarket ON, East Gwillimbury ON, and Buffalo NY. I am trying to disprove Buffalo NY as a birth place.
The evidence I currently have is the 1940 census, the SS-5 for Mr. Turner, and birth certificate and marriage certificate for his daughter. The 1940 census does not indicate that Mr. Turner or his wife was the informant and I believe the SS-5 was filled out by the employer rather than by Mr. Turner (explained in the proof summary). However, because of the birth certificate and marriage certificate (which was filled using the birth certificate of the daughter) which it is possible Mr. Turner was the informant, I decided to check out the New York State Vital Records Index. The index for the year of Mr. Turner’s birth does not list a William Henry Turner born in that year anywhere in New York State in the index. Would this be enough to prove negative evidence or should I contact the clerks in the communities he would have been in?
The real question you’re asking is, “have I engaged in reasonably exhaustive research?” — the kind of thorough research that underlies all reliable genealogical conclusions. And here’s the definition of that concept: “Thorough research attempts to gather all reliable information potentially relevant to the research question, including evidence items conflicting or consistent with other evidence items. Thorough research, therefore, aims to consult all potentially relevant sources.” BCG, Genealogy Standards (Nashville, TN: Ancestry, 2014), 14 (Standard 17). So you need to ask yourself whether you have gathered all reliable information that could answer your question, and whether you have consulted all potentially relevant sources. If not, well…
So the question I should be asking is, given all the other evidence I have regarding Mr. Turner’s birthplace (and I have more evidence than I listed above), would any other researcher reading my work, expect me to have gone to the town clerks of 3 communities where the family resided at some point in time to try to obtain a birth certificate considering no listing shows up in the index and all other records combined?
And whether, in the back of your own mind, you’re wondering why you didn’t go to those clerks to check…