Determining Certainty

[saddlers]

A bit of a general query... I know nothing is strictly certain in Genealogy, however there are branches where certainty (in terms of paperwork) can be almost be guaranteed, however on other branches there may be a good indication but still that nagging doubt remains. This also gets more complicated the further back you go because the evidence becomes more uncertain.

I often find myself checking information again and again every time I get back a bit further just to make sure I am not going off track and it can be very time consuming, however I just cant help myself. I often wonder if anyone has devised an algorithm or method of determining a certainty rating that could be added against an individual in a tree?

For example we all have those ancestors who were spot on with the paperwork and seem to be recorded on every census with little change of address and consistent family members, and also have birth, marriage and death certs that all reinforce this information....then we have the ancestors who seem to have gone off radar once in a while, changed the spelling of their names or their age or you may struggle to find a certificate to accompany the person and that inevitable doubt creeps in.

I am just curious how people deal with these scenarios, I have tried searching for algorithms and certainty ratings but cant seem to find what I am looking for.....I suppose another way of looking at it would be is there a genealogy rule book

[Megan Roberts]

There is no definitive method.

What I do is I write all assumptions, presumptions, methodologies etc., so that if at some point I come across the golden nugget of information that challenges previous thinking I have something to reference that against.

For instance, in the case of one of my Great great grandfather's we have been certain who his father was because we have never found a definite baptism for him. We do know that his father had to have been one of three brothers, but not which one. One of my aunt's who originally did the family history thought that it must have been the only one that was married at the time, but I have since found other documents suggesting another brother. So I have written a four page note which builds my case, and includes small things like he gave his only son the same name as the brother who I think is his father.

That note is available for all to see, and challenge, and that I think is the best way forward, rather than claiming as definitive.

[Ladkyis]

My great grandmother and some of her brood were gold-medal standard liars. One of her sons had three marriages but didn't end the first one before embarking on the second and then his second wife told her children he was 'lost at sea' when he had actually married another woman and emigrated to America........... It has taken 20+ years to discover all this and as I go back further I have learned that there is no easy way. Checking and re-checking is the only way to keep track of these crafty ancestors.
Finding the ones who drop off the radar is much much harder than finding the ones with the criminal records as the criminals have descriptions on record. I have newspaper reviews about my actors thank goodness because the official records don't have them under their own names - stage names or using the name of another family member or they simply don't put themselves where they can be counted. Then there are ages and birth places ............................ *sigh* If they don't want to be found then it is very easy for them to hide. As I say I have been chasing them for 20+ years and my Dad was doing it for at least 10 years before that so one day............................. one day

[saddlers]

That makes me feel better, its nice to know I am not alone

[Pam Downes]

I think a lot of it depends on the name. If you're looking at John, William, or Mary Smith, you can have doubts even in the 1900s let alone further back. I've got a William Sharp marrying a Mary Wright circa 1810 and I think they will be the last lines I look at because I know there are lots of Sharp families in the surrounding villages.

A lot of my lines are in Lincolnshire and Lincs FHS have published loads of PR transcriptions in deaneries on CD, which means that it's very easy to check for a name in x number of places between 1754 and 1813 in a very short space of time. If a surname only appears once or twice then you know you need to look in either another deanery or another county.
Many other county FHS have published transcriptions, though I find often it's by individual parish which can make it expensive to buy, and more difficult to easily find how often a name occurs in an area. The good news is that some FHS's indexes are on FMP, and there's also FreeREG, where you can search for say Joe Bloggs born 1800-1820 born in a particular county, though always remember you need to check which places have been transcribed. You also need to check with the county record offices as to which PRs exist and which have been lost to fire, flood, and mice.
Plus of course, many more images for PRs are being put online via FMP, Ancestry, and FamilySearch, etc, which means it's now much easier to 'visit' records held in county record offices than in ye olde days (pre-2015 : biggrin.

(Somewhat off-topic, but:
Anyone who says they can't afford the subs charged by the likes of FNP and Ancestry need to remember that if it wasn't for these companies they would never be able to afford to do any of their family history because they would have to travel to the county record office to access records. And before FreeBMD, you had to hope local archives had a set of the GRO fiches else you had to travel to London to search the indexes.)

I think it boils down to how common is the name and how complete were the records you've searched. Plus it's worth remembering that (without DNA tests) the only ancestor you can be 100% certain of is your mother.

Pam

[macwil]

. . . Plus it's worth remembering that (without DNA tests) the only ancestor you can be 100% certain of is your mother.

Pam

Even that may not be true any more in these days of IVF, gene therapy and surrogate mothers.

And don't forget adoption. I can't remember how many times I've seen stories of adults discovering they were adopted on their 'parents' death.

[Guy Etchells]

=Pam Downes;665878 Plus it's worth remembering that (without DNA tests) the only ancestor you can be 100% certain of is your mother.

Pam

Glad you said “ without DNA tests” because with DNA tests even that certainty is put in doubt.
E.G. https://en.wikipedia.org/wiki/Lydia_Fairchild

DNA science is in its infancy still and very little has been proven as fact. It is assumed that a persons DNA is unique but that was also assumed to be true of fingerprints and has since been shown to be a false assumption.

Many of the claims promoting DNA are flawed but that does not mean that used with care it can be useful for family history, but it is only one tool of many.
Many new genealogists will not be aware but the use of DNA today is very similar to the great new tool for the Genealogist of 1978 the IGI (both are/were very accurate in what they found) the flaw in both is in the interpretation of the data.
In the case of the IGI genealogists used it as an index of parish registers which it was not rather than an index of the ordinances of the Church of Jesus Christ of Latter-day Saints, which it was/is.

DNA is simply a record and as with all records to use it accurately the genealogist/family historian must understand what it actually records rather than what they imagine it records.
Taken to the extreme DNA could prove that everyone of us is related to any racehorse or cabbage you care to mention (that encompassing DNA is excluded from the results by the testing companies but it is still in everybody’s DNA).

Cheers
Guy

[NicolaYoung]

A bit of a general query... I know nothing is strictly certain in Genealogy, however there are branches where certainty (in terms of paperwork) can be almost be guaranteed, however on other branches there may be a good indication but still that nagging doubt remains. This also gets more complicated the further back you go because the evidence becomes more uncertain.

I often find myself checking information again and again every time I get back a bit further just to make sure I am not going off track and it can be very time consuming, however I just cant help myself. I often wonder if anyone has devised an algorithm or method of determining a certainty rating that could be added against an individual in a tree?

For example we all have those ancestors who were spot on with the paperwork and seem to be recorded on every census with little change of address and consistent family members, and also have birth, marriage and death certs that all reinforce this information....then we have the ancestors who seem to have gone off radar once in a while, changed the spelling of their names or their age or you may struggle to find a certificate to accompany the person and that inevitable doubt creeps in.

I am just curious how people deal with these scenarios, I have tried searching for algorithms and certainty ratings but cant seem to find what I am looking for.....I suppose another way of looking at it would be is there a genealogy rule book

Hi Saddlers,

I have been wondering this for some time. A method to quantify accuracy needs to exist. It seems unlikely that someone didn't invent it already. I have the basics of a method in my head, but as I've only looked at my tree it might not be attributing the weighting of data/proofs accurately and I don't want to reinvent the wheel. Your post was the first in Google which is worrying. Especially as no one seems to know of method.

If you or any genealogists would like to get together and create one that maybe will become standard.

I attribute 20% for birth or marriage certificates. 10% for death and cencus records that they are on, but so is another person I think is right is on. 30% if it matches with fAmily stories. When we visited Bradford my dad always said someone's sibling died in the black waters. So if I find someone drowned and lived near a river called black river or something I will give 30%. 5% for other records.

So my great grandfather, lives at the address I have from my great aunty 30%. He has a cencus record living with my grandmother 10%. I have his marriage certificate 20%. I have baptism record and 3 more cencus records 40%. Therefore 100%. Of course it will sometimes go over 100. But I wanted to use percent so it means something. I'm sure this can be improved. I was hoping someone else had invented something.

[Peter Goodey]

Certainty of what?

On a man's marriage certificate, the certainty that he married the bride is pretty high. The certainty of his father's name being accurate is pretty low until such time as supporting evidence can be found.

[saddlers]

Perhaps my comments were not explained correctly, Nicola has the basis of what I am trying to explain.

Each individual within our family trees has documentation to support the theory that the person we have assumed to be our ancestor is actually our ancestor. I understand there can be no absolute guarantee, but the more documentation that exists to support the individual being correct could be assigned a weighting, so that the more documentation that exists that aligns could be used to determine some form of rating/percentage to visually give an indication as to the certainty of that data being correct. I think percentages may not work because it would be too difficult to get the split correct.

For example if you had an individual who you have all the BMD certificates for and the data matches for the generation above and below in terms of ages/profession etc and you may have a witness that also ties in this would be a good indicator of accuracy, especially if census information, baptism information, military record also tie in to the correct ages, addresses etc. therefore the visual percentage of accuracy would be very high

However a person where you may have the BMD certs but there is an age inaccuracy, or a profession that has changed would not hold as much weight, and therefore you have a visual indicator of this fact.

It would require weightings to be given to sources as Nicola has indicated above, I just assumed that someone else must have given this some thought before and am quite surprised that no system exists based on the documentation below.

I would give more weighting to the information on a Marriage/Birth cert than I would to a Death cert or census information, but I am not sure how you could fairly decide which documentation would carry the most weight and then how each data entry point on these documents would affect that base rating...my gut instincts would be something like:

Baptism Christening - 10 points
Birth Cert - 30 Points
Marriage Cert - 30 Points
1841 Census - 3 Points
1851 - 1901 Census - 5 Points per census
1911 Census - 10 Points
1939 Register - 15 Points
Military Record - 15 Points
Death Cert - 10 Points

Then you could subtract points for an inaccuracy depending on the discrepancy......this is only in its infancy, but there must be something out there along these lines...surely