XY Family Tree

"The concepts behind XY Family Tree"

Tall trees - from present to past (ancestors) and from past to present (descendants)

OK, so you decide to explore a particular name back into the past from a certain starting person, usually yourself or maybe one of your parents. This research usually concentrates on one particular family name and traces it into the past. It becomes impossible to trace all the ancestors as they double up with every generation and you need to drop some lines because... well maybe you'll get back on that later. At least you can give this tree a family name - usually the highest, or ground level male on the male side.

Tall trees are generally the most difficult to prove and seldom have any pictures with which to illustrate them. Unless you have a provable connection to an important or royal family, it's unlikely that you can have a very tall tree.

Spreading trees - cousins and other living relatives

With a spreading tree using horizontal connections, you probably have a good chance of finding your living cousins, second cousins and removed relations. As the world's population has expanded so much in the last 150 years there is a good chance that you share a common ancestor with hundreds of other living people. Spreading trees are harder to name because there are so many significant people in such trees. In a small static community a person will share common ancestors within very few generations. As people migrate into larger communities the chance of marrying a cousin is reduced, so common ancestors are only found in more distant generations.

The good thing about spreading trees is that they are much more likely to have pictures and other media available (subject to permission). The downside is that there are many more privacy issues.

Taking cuttings - creating a new tree from an existing one

XY Family Tree has a facility to make a new tree based on a selected person in an established tree. This creates a new tree as an extract from the original, that includes all ancestors of that person, all descendants from those ancestors and all spouses of the ancestors. Effectively this picks up all blood relations of the selected person. Think of this like a fountain and cascade; where the water shoots as high as possible and all the cascade results from the very highest (earliest) reaches.

Unconnected people

In XY Family Tree you can enter people that are not connected with the actual ancestry or descendancy but who have a peripheral or interesting connection, such as the relationship between Lorenzo Medici and Michelangelo. Such a relationship is entered in XY Family Tree as "other relationship". This offers all sorts of possibilities to display information without bending the strict rules of biology - that a person can only have one father and one mother.

The effect of errors (date, parentage)

Errors of date may lead to confusion but otherwise might be simple errors. Unfortunately, date errors of any sort are very likely to lead to more serious errors, errors of parentage. Errors of parentage invalidate all relationships before that point and any connections horizontally that depend on the earlier connection.

Dates are always a problem. They are a problem for at least three reasons:

• a date is not known at all - the field is empty and cannot be used
• a date is vague - "before 1920" is not a date, nor is "unknown"
• a date is written as text and may be formatted differently to expectation e.g. "10/11/07", could be intended to mean "2007-11-10", "1907-11-10", "10/11/1807", "11 Oct 1707", "10 Nov 1607".

XY Family Tree allows you to choose dates with the year (as 4 digits) on the left or on the right. Only the year part is published on the website; this is for simplicity. All timeline views are based on a year - so you need to be consistent in your use of dates.

Privacy

XY Family Tree allows several levels of privacy. For individuals who are, or might be, still alive, forename can be hidden, family name can be hidden and dates can be hidden. Additionally, on the website, there are a three settings of privacy for your tree; ranging from total visibility to access only by password..

Media and other interesting documents

Many genealogists gather photographs, audiotape, film and video recordings of recent ancestors. The earliest photos are unlikely to predate 1850, film and moving images unlikely before 1920 and audiotape unlikely before 1940. So, if your family tree goes back before 1850, and many trees go back way further than then, the use of photos and media clips is of little relevance. Media is more use in a spreading tree where the majority of connections are horizontal. Of course there is always the possibility of a picture of a painting, but few paintings were made for most of us.

Other interesting documents could be certificates. Certificates could go back way before media evidence but can only be displayed on a website as pictures of certificates.

I read many interesting articles on how family tree programs should handle media items and have attempted to implement these on the PC. Your best and most interesting views of your recent ancestors are handled well on a PC. The website view of your family tree is more simple but can nonetheless use media files.

Charts - exclusion, honesty, emphasis

A chart that is intended to show a particular emphasis on a certain person or branch of a family tree must deliberately exclude information that would be important in a different chart.

Because XY Family Tree has been designed as a simple and honest way to display charts of ancestors, descendants and family connections, it has no facility to emphasise particular people other than person in the focus. It does, however, have the facility to extract a branch for a chosen individual into a new file that can be displayed in the various standard ways. The extract is like a fountain; it selects all ancestors of a person as far back as they go (shoots the water as high as it can) and then all the descendants of all of these people (the cascade).

Numbering systems

Before computers there were many attempts at making numbering systems that were intended to simplify the connection between people, so that relationships could be deduced if you knew how the system worked.

I believe that numbering systems are now obsolete as computers can calculate relationships by using their own internal logic. Humans therefore, have no need to assign numbers using any other system.

See this link if you are in any doubt: http://www.saintclair.org/numbers/numlastw.html

"The Principal Truths of Genealogy"

The Two Fundamental Truths

1 Each Individual has a single biological Father and a single biological Mother

2 The Father and Mother may, or may not, have been connected in a “Formal” relationship

The Biggest Problems with The Principal Truths

The recorded Father and Mother might not be the biological Father and Mother

Any wrong information (or assumption) invalidates all dependent information