A couple of experiences recently have brought to mind the question of how certain can we be about the information we are putting in our family trees.  Some of the data may only be hearsay, details dredged up from an elderly relatives memory, for example.  These details may be wrong.  Other details will be obtained from official records.  These may be assumed to be more reliable, but even these are often only as accurate as the information supplied by the informant.  For example the person registering a death may not be sure of the deceased's date of birth, or may think they are older or younger than they are.

Even the data on a birth certificate is only what is supplied by the parent or parents that are registering the birth.  A mother could give her husband's name as the father even if she knows that he isn't.

Similarly census data is supplied by the head of the household. This is usually the "man of the house".  Are we sure that he knows the exact ages of all the children, or the servants' or boarders' birthplaces? 

The best indicator of truth is consistency across a range of different records. But even then we only know that the information is probably correct. It could still be either a mistake perpetuated or possibly something deliberately hidden.

Census data is particularly useful as it provides relationship data and corroboration of birth dates and places, and occupation and residence data that isn't generally available anywhere else.  Census entries may contain errors but often this can be spotted by checking census data for other years.  However, even when the data is inconsistent from one census to another it may not necessarily be wrong.  I recently had a case  where one entry said the person was born in Shalfleet, one said Newbridge, and the rest said Calbourne.  The family appear to have been living in the village of Newbridge at the time, but this in the parish of Shalfleet, on the border with the parish of Calbourne.  The birth was registered in Calbourne, which was the Poor Law Union district that included the parish of Shalfleet. So they were all correct!

The period before the Censuses began to record relationships in 1851 gets particularly fraught with potential errors.  The 1841 census may list a household and it is natural to assume this is man and wife and their children, but it could be that some of them are cousins who are staying with them and have the same surname.  There are lots of other possibilities too.

Before 1841 we are reliant mostly on Parish Register entries for baptisms, marriages and burials.  This is where things get more difficult.  Most, but not all, children were baptised and most couples married, though not always before a child was born. Almost everyone was buried.  It is important to remember that the register date is that of the baptism, marriage or burial. Burials can usually be assumed to be at most a few days after the death occurred.  However, the time interval between birth and baptism can be very variable, from days to years.  It is not uncommon for several siblings to be baptised at the same time! 

The further back in time we go the less likely it is that the Parish Register has survived, either the entire volume may have been lost or individual pages may have been lost or damaged such that only some entries are legible.  Before 1538 records were not generally kept so there is likely to be no evidence of an event.

Some times the Register entries were copied from earlier lists and errors have crept in as a result. A common sort of copy is known as the Bishop's Transcript.  These were made for the local Bishop by copying the Parish Register entries.  The Parish Registers themselves remained with the parish.  These were usually made annually but the Bishop did not always receive a transcript from every parish.  Copies can be very useful, however, if the originals are lost.  There are many cases where Parish Registers have been lost but the Bishop's Transcripts exist.

The problem for the family historian is using these records of individual life events to produce a coherent family history.  It may be reasonable to assume that a sequence of baptisms where the parent's names are the same corresponds to a single family, but what about the parent's marriage?  If we find a marriage with matching names in the same parish just before the baptisms start, then it is probably the parent's marriage but it could be coincidental.  It is likely that there are relatives with the same surname as the father living in the same area, maybe the marriage was one of them?

Assuming that the marriage is correct, we can start looking back for the baptisms of the couple.  This is an even more uncertain step. There may be no records of a corresponding baptism (i.e. same name and right sort of age).  It may be that the record has been lost or that the event occurred in a different parish.  The further afield that we start looking, the greater the likelihood of finding an apparently matching record that isn't actually the right one.  Or we may find more than one possibility, and then there is probably no way to determine the correct one without further information.

With so many possible ways to go wrong how can we ensure that we build trees that are accurate?

The simple answer is, of course, that we cannot ensure complete accuracy.  And unfortunately, there is no correct answer that we can check against. 

What we can do is endeavour to make trees that are as accurate as possible.  That fit all the data we can find as well as possible.

We need to:

  • Find as much relevant information as possible
  • Use multiple sources were possible (e.g. civil records, church records, census data, occupational data)
  • Be aware of potential errors in the source data
  • Use primary data where possible
  • Check data from indices and transcripts against the originals if you can
  • It's OK to proceed on the basis of unwarranted assumptions only if you note them as such
  • Accept that we may make mistakes
  • And most importantly, keep an open mind.  Be prepared to rework parts of trees if new data shows the current understanding is incorrect

Ultimately we can only produce a tree with as many supporting sources for each element as possible.  And the detective work involved in working out the tree that best fits all the available data is part of the fun of genealogy!

As an interesting exercise in the limitations of even primary data sources you might like to consider this question posed by Vanessa:  Can you prove that you were not born in Vietnam?