Methodology

Different charts for different purposes

The family tree chart is a familiar part of family history research. But are we using it properly?

The family tree is a tool and like all tools, we need to choose the best tool for the job.

It is not as simple as deciding whether we need a descendancy or ascendancy format.

What is your purpose?

Getting the most out of charting requires us to consciously think about why we are creating a chart and what we want to achieve. The answer to this question will not be the same on every occasion, which means we need to create different charts at different times.

Family tree charts can be used for different purposes, which I divide into three categories:

  • documenting – charts help us record key bits of information about the people in our family tree and how they are related to each other
  • illustrating – charts help us share a graphical representation of our family history with others
  • analysing – charts help us analyse our family history and advance our research.

Trying to achieve all of these purposes in a single chart is rarely successful.

What format of chart do you need?

The first format decision is a choice between an ancestral chart or a descendancy chart.

  • An ancestral chart starts with you or another person and moves back through the generations of ancestors.
  • A descendancy chart starts with an ancestor and moves forward through time listing the descendants.
Ancestral chart
Descendancy chart

The focus person for these two formats are different. The chart is illustrating how people are related to that focus person. The people that are included in an ancestral chart and a descendancy chart differ, even if the chart is about the same family lines.

Unless you choose otherwise, an ancestral chart will show all four of your grandparent lines; while a descendancy chart will just show the grandparent line that relates to the ancestor who was the focus person.   

The second format decision is the type of chart.

The line chart is the most commonly used format. It is useful for all three purposes – documenting, illustrating and analysing. I like it best for documenting, but it can also be used for analysis as shown by my Tree Health Assessment Tool.

An example of a line chart, but there are many variations on this format

The next most commonly used format is the fan chart. I like this format for illustrating and analysis purposes.

The fan chart is a neat format and tends to fit nicely onto an A4 page. I find that a fan chart is a good format for sharing with people who are not family historians as it is easier for them to interpret. However, it cannot store as much information as the line chart so it may not be the best choice if your main purpose is documenting.

For analysis purposes, the fan chart clearly shows where you have gaps in your family tree. In DNA analysis, it can be used to illustrate which people have been confirmed by DNA.

Fan chart showing confirmed ancestors in lime green, tentative ancestors in blue and unconfirmed in white. It also shows gaps in the tree and how many generations have been researched.

Both the line chart and fan chart formats can be either an ancestral chart or a descendancy chart.

Some family history and charting software also provide other chart formats, such as trellis, dandelion, bow tie and fractal trees.

What information do you need?

A key question for your chart is – Which people do you need to include in your chart to achieve your purpose?

Is it sufficient to include just the direct line, or do you need to include extended family such as siblings, multiple marriage partners, step children, adopted children? Are there particular lines that you want the chart to focus on?

The answer to this question feeds back into your choice of format. If you only want to include your direct line, then any format will suffice. A line chart is often the best choice if you want to include extended family or focus on particular lines.

A relationship line chart can be used to show the direct line between two people

Another important question is – What information do you need to include in your chart to achieve your purpose?

Names are usually essential, but not always. I have seen many charts produced for DNA purposes that do not contain names.

Birth and death dates are useful, because they help to distinguish between the people in the tree. Alternatively, unique identifier numbers that link into your research documentation may be sufficient in some cases.

If you are creating the chart to document your family tree, then you will probably want to include additional information such as birth and death locations, marriage dates and locations, and burial locations. This makes the chart more useful as a summary of your family history which can then be used for further research.

If the purpose of the chart is analysis, then information relevant to that analysis should be included. For DNA analysis that may include segment size, chromosome data, ethnicity data and clustering data.

Charting for DNA purposes is a big topic, which I cannot explore in detail here. If you want examples of how to use charting with DNA analysis, take a look at:

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