Methodology, Sources and resources

How many sources do you need?

Sources provide us with information about our families, events they participated in or which impacted on their lives, and the places that they lived or visited. The big question is, how many sources do we need to compile an accurate family history?

There are actually two parts to this question:

  • how many sources should you use, and
  • how many sources should you cite.

I am not sure what other researchers do, but I cite all or close to all of the sources that I use on the master version of my family tree which I keep on my computer. My online trees tend to have fewer citations.

One source is better than none

If you have done any reading about the methodology of family history research or attended any lectures on the topic you will already know that a family history without any source citations is considered to be virtually worthless.

It may be accurate and the creator may have used hundreds of sources, but without citations only the creator of the family history will know that. Others will be reluctant to accept it or to use it, because each piece of information would have to be verified through further research. And, without citations the creator of the family history will find it more difficult to progress their research.

Extract of birth certificate of my great grandfather James Hen(d)

So, one source citation for each piece of information is better than none. It shows you and others where you got the information.

However, all sources can contain errors, gaps in information or deliberate alterations. So, relying on one source for each piece of information is unlikely to generate an accurate family history.

Two sources are better

If you use two sources for each piece of information, you can compare the information. If the information between the sources is consistent, then you and others can feel more confident that the information is correct and that your family history is accurate in that respect.

Two sources for my great grandfather Thomas Flanagan

Confidence in the information from two sources will increase if:

  • the sources were created independently of each other
  • the sources are considered to be reliable
  • there are no inconsistencies in other sources relevant to that individual.

Some would add to this list that at least one of the sources needs to be an original source. I do not disagree with the value of original sources, but I would include that under the dot point about using reliable sources.

More is best

Even two independent, consistent and reliable sources may not be sufficient.

The more sources that you have, the more likely you are to detect errors or inconsistencies. Having more sources increases confidence that your family history is accurate.

Three sources for my 6x great grandfather John Townson

You need to use your own judgement, but I would suggest that you need more than two sources:

  • if there are any errors, gaps or inconsistencies in the two sources even if they are not related to the information you extracted, because this suggests that the sources may not be as reliable as you would like
  • if either or both of the sources were not contemporary with the event
  • if the information was secondary information – that is, it was provided by an informant who did not have first-hand knowledge or first-hand experience of the event
  • if the information provides indirect evidence, which requires inference to reach a conclusion
  • if the identity of the people involved is in question – i.e. if you are unclear whether the person in the source(s) is the right person
  • if getting that piece of your family history accurate is particularly important – for example, the name of a parent or where a name change is involved
  • if other researchers disagree with your conclusions or have different information and their family history appears to be well researched.
Methodology, Sources and resources

How can you incorporate DNA evidence into your family tree?

You have had your DNA tested. You have analysed the results and reached some conclusions. Now you have to decide what changes you need to make to your family tree.

I am not going to talk about how to reach a conclusion using DNA evidence. That topic has been covered extensively elsewhere. What I want to discuss is how you can take the information and evidence obtained from autosomal DNA testing and apply it to your family tree.

What can DNA tell us?

DNA testing provides evidence about biological relationships between people who have been tested. From that information you draw conclusions about the identity of your ancestors.

This can be very useful for your family tree, because it might:

  • support what you have learned from documentary sources
  • refute what you have learned from documentary sources, or
  • fill gaps in your family tree.

What might you add to your tree?

A DNA source citation:

If your analysis of DNA matches supports your conclusion about the identity of someone who is already in your family tree, you might add a DNA source citation to their profile to document that the evidence has been strengthened. This is sometimes referred to as ‘confirming’ a relationship.

Example source citation from Wikitree for DNA evidence of a paternal relationship, where the father was the son of Samuel Bassett and Mary Doolan
Source citation from Wikitree setting out the DNA evidence for the father of my great grandmother

An identified person or group of people:

If you are able to gather sufficient evidence to support a conclusion about how a DNA match is related to you, you could add that match to your tree. If the ancestral line of that match is not already in your tree, you could also add that line to document how they are related to you via your most recent common ancestor (MRCA).

An unidentified person or group of people:

If your DNA match has supplied a family tree, you can add them to your tree even if you do not yet have sufficient evidence to determine how they related to you. In this case you add the match as an unlinked person and use their tree to investigate your relationship. Adding a group of related matches and combining their trees is often a useful strategy. More on this point below, under ‘Confirmed or hypothetical’.

Extract from an Ancestry family tree showing Bernard Lyons, wife Elizabeth Flanagan and Elizabeth's brother Francis Flanagan.
A large group of DNA matches suggested that I was related to Elizabeth Flanagan. I had her in my family tree for over a year before I worked out how we were related.

Extra documentation:

If your analysis confirms how a DNA match is related to you and they have extra information about family members, you might add that information to your family tree. This could include photos, events that they participated in or other details of their lives.

DNA source citations should be included in all of these circumstances.

What might you alter or remove from your tree?

Remove a person or family line:

If DNA provides evidence that you have the wrong people in your family tree, you may have to delete a person or family line. If you are uncomfortable with deleting them entirely, you could just unlink them and leave them in your tree.

Alter a relationship:

If DNA provides evidence that you have the right people in your tree but that the relationships are incorrect you will need to alter the relationships. This usually involves unlinking and reconnecting to establish the correct relationship.

If DNA provides evidence that a biological relationship is incorrect but they are still part of the family in some way, you might like to keep them in your tree but change how they are related to you. For example, if DNA demonstrates that someone was adopted you could add the biological line, keep the non-biological line and record the adoptive parents as such.

Extract from an Ancestry family tree showing biological parents and adopted parents
My father has two sets of parents

What do you need to document?

The mechanics of deleting, unlinking and changing relationships in your family tree will vary depending on where you store your tree. Just remember to back up your tree before you make any changes, in case you want to revert to the old tree at some point.

Source citations:

Source citations are essential. Here are a few useful articles on this topic:

Statement of evidence: 

Sometimes a source citation is not enough and you may need to include a statement that documents the evidence you used to reach a conclusion (often referred to as proof statements and proof arguments). You could include these as notes on the person’s profile or attach a separate document as media.

Extract from Ancestry family tree describing the evidence for a child of Catherine Flanagan and Alan Everett
Evidence statement on an Ancestry family tree

Identifying DNA matches: 

Identifying or labelling your DNA matches in your family tree helps with future analysis, especially if you have not yet gathered sufficient evidence to confirm the relationship. The most common methods are to use profile images, tags or hashtags. You can also identify members of a cluster or group in this way.

Ancestry allows you to add the tag ‘DNA match’ to people in your tree
Data sheet for an individual from Legacy family tree software showing the hashtag symbol and a DNA event or fact
Two options for identifying DNA matches in Legacy family tree – hashtag and an Event/Fact

Identifying MRCA:  

It can also be helpful to identify the most recent common ancestors (MRCA) of a group of DNA matches and add information about whether or not their relationship to you has been confirmed.

Ancestry allows you to add tags and you can also add a DNA confirmed image as the profile picture

Identifying the line between a DNA match and MRCA:

Marking the people in a direct line between a DNA match and your most recent common ancestor can also assist your research. In the image above, Ancestry allows you to add a tag ‘DNA Connection’ to indicate that ‘This person is a relative on the path between a DNA Match and a common ancestor.’ A DNA connection image can also be added to online family trees or your family history software.

Blue and purple DNA symbol
Example icon that can be added to the profile pictures of the ancestral lines of a DNA match

Confirmed or hypothetical: 

If your research method involves adding people to your family tree before you have confirmed that they belong there, then you should have a means of distinguishing between the confirmed people and the unconfirmed people. Some may shudder at this approach, but it is one that I myself use at times because I find that having them in my tree makes them easier to research.

An example of this situation might be where you add the family tree of a DNA match, mark them as unconfirmed, and then set out to verify their tree with further research. An alternative to this approach is to create separate family trees for unconfirmed matches.

Other information: 

You might like to store other information about DNA matches on your tree, to make the information more accessible. If your family tree is online, be careful you do not share any information about matches which violates their privacy.

You could record information such as email address, the name and URL of their online family tree, their location and their ethnicity as an Event/Fact on the profile of your DNA matches in your family history software.

Your own ethnicity predictions: 

Your ethnicity predictions could be stored on your own profile in your family tree as an attached document (media) or as an Event/Fact.

Research questions or plans: 

DNA test results will generate research questions and hypotheses to be tested. If they relate to a specific DNA match or MRCA, you could keep them handy by recording them on the relevant profile in your tree.

Privacy issues

Privacy is a complex issue when documenting DNA evidence. If you are interested in exploring this issue, I would recommend The Legal Genealogist blog.

Further information

My articles:

DNA Sydney website

Methodology, Sources and resources

Five tips to make citing sources easier

Every good genealogist knows that they need to cite their sources but many still find it a challenge. Here are five tips to make the process easier.

Keep the purpose of a source citation in mind

Thinking about the purpose of a source citation helps you focus on the information that needs to be included in it so that it achieves that purpose.

You might like to read the blog posts I wrote last year on this topic – Four Good Reasons to Cite your Sources Part 1 and Part 2.

After writing your citation, examine it closely and ask yourself:

  • Does the citation contain all the information that you or someone else would need to find the source again? Is the information complete and unambiguous?
  • Does it appropriately acknowledge who created the source?
  • Does it provide information to help you and others evaluate the reliability of the information within the source?

Compile a sample set of citations

Sources can be grouped into three categories:

  • sources that we use all the time – such as birth, baptism, marriage, death and burial records
  • sources that we use often – such as wills, probate records, land records, census, electoral rolls, newspapers, books, journals and website pages, and
  • sources that we use less frequently – such as DNA, unpublished archival records, maps, oral history, personal communication, personal reminiscences and social media.

Gather 1-2 sample source citations for each type and store them in a file that you can refer to when you need to create a new citation. Start with group 1, then move onto those types in group 2 that you use in your research. Samples for group 3 are optional and can be added whenever you create them.

Extract of transcription of death certificate for Thomas Flanagan, died 14 January 1928, Lidcombe, New South Wales, Australia

If you research in different geographic areas, you may find it useful to have sample citations from each area as there may be differences between the sources. A source citation for a UK census, for example, is different to one for an Australian census.

You can find sample citations in guides, on the web and from lectures.

Master list of citations

Keeping a master list of all the citations you create has a number of benefits.

A master citation list:

  • saves you having to reinvent the wheel when you use a source that you have used before
  • gives you more samples to copy from
  • helps you be more consistent with your citations
  • documents all the sources that you have used, which may help you identify new sources to examine.

Family history software generates a master list of citations as you create source citations.

You can also compile a master list yourself, in a spreadsheet or other program.

My blog post series about using Excel does not specifically illustrate a master list of citations, but reading those posts will give you general instructions that you can follow. I would start with columns for Who: author/creator, What: title/description, Where: publication details, When: date, and Other details. You can then add extra columns, if needed.

Use a guide

There are many guides about creating source citations. My advice would be to find a fairly simple one, written by either a genealogist or a historian. I have nothing against librarians, but their specialty is published materials whereas we use mostly unpublished materials. Also check for guides from the repository where you find a source, as they often suggest how to cite their sources.

Cover of book called Citing Historical Sources, A Manual for Family Historians, by Noeline Kyle

Source citation tools

If you use family history software, invest some time learning to use the source citation tools within the software.

If you use Legacy family history software, you might be interested in attending the March meeting of the Society of Australian Genealogists’ Legacy Software Users Group, where I will be running a session on this topic.

Methodology, Sources and resources

What’s wrong with this source?

Errors in historical sources are one of the main reasons why family histories become inaccurate.

Identifying errors

The first step in dealing with errors in historical sources is to identify them. There are three main types:

An error in the recording or transcription of information, such as a typographic error or spelling variation.

Death certificate, NSW Australia, naming Thomas Flanagan and children Mary, Frank, Elizabeth, Bridget, Katherine, Jane, Alice
A simple error – Katherine spelled with a K instead of a C

An error of comprehension or misunderstanding, such as when a name is misheard or the information for one person is transferred to the record of another.

Birth certificate for Catherine Agnes Flanagan, NSW Australia, demonstrating error in the name and birthplace of her mother
Perhaps a typo or perhaps it was misheard – Mother’s surname entered as Wolan instead of Dolan. A second error in the spelling of Leitrim, likely due to the recorder being unfamiliar with the place.
Birth certificate for Henry Albert Hend, NSW Australia, demonstrating error in father’s name
The name recorded for the father is actually the child’s name.
Death certificate, NSW Australia, for Thomas Flanagan, died 1928, with an error in his place of birth
Thomas’ wife’s place of birth has mistakenly been recorded as his place of birth.

Deliberate alteration or omission of information.

Extract of death certificate, NSW Australia, for Christina Malchow, died 1893, with details of children omitted
A deliberate action to omit information about a woman’s children.

The causes of errors are numerous, but they are more likely to occur when the informant:

  • cannot read and/or cannot check what was recorded
  • has an accent that is difficult for the recorder to understand, or
  • does not have the correct information.

It is important to remember that all sources can have errors. However, there are some general statements that can help you evaluate the likelihood of errors.

  • Original sources tend to have less errors, because they are the first version of a source. Errors tend to creep in as other sources are derived from the original.
  • Contemporary sources tend to have less errors, because they are closer to the event and are more likely to have been created by someone who participated in the event or were at least part of the society in which the event occurred.
  • Official sources tend to have less errors because they often follow regulated formats and content, and may have been created by an experienced record maker.

Things to be wary of

Errors in sources may not always be obvious. It is best to assume that each source has errors until proven otherwise.

Sometimes it is difficult to determine where the error lies. For example, when two sources contain different information it can be difficult to determine which one contains the error.

Be careful not to dismiss inconsistencies or explain away an error, unless you have evidence to back up your explanation. This is particularly important for changes in names and locations.

My tips for dealing with errors

  1. Check that source again
  2. Analyse the source and the information more thoroughly – see my other articles about analysing sources
  3. Check different versions of that same source
  4. Compare the information in that source to other sources about same person
  5. Compare the information in those sources to other sources about the family
  6. See what other researchers say about that family.

Of course, the error may not lie in the source but instead be the result of your research method or your analysis.

More information

Come to my lecture, Fixing Errors in Your Family Tree, for the Society of Australian Genealogists on 29 January for more discussion and tips on this topic. 

Read my other articles about research methodology and sources, by clicking on the blog post category to the right of this article.

Carol Baxter’s book, Help! Why can’t I find my ancestor’s surname? provides useful explanations for distortions in surnames, which may also help you understand other errors in sources.

Sources and resources

Using maps in family history

Maps are symbolic representations of places. So how can we interpret them to inform our family history?

Maps can be extremely useful in family history, but they are a little underutilised. Perhaps if we learned how to understand them better, we could get more use out of them.

Maps can, of course, show where your ancestors lived and the features around these places. Knowledge of nearby features, such as mountains, rivers, forests, roads, railways and big towns, can reveal details of ancestral lives. For example, mountains tend to impede travel, while roads and railways facilitate it. Big towns may be where baptisms and marriages took place and where records may still be found.

Maps can provide information about the distance between places, allowing you to assess the likelihood that your ancestors moved between them. By studying a chronological series of maps, you may be able to determine how a settlement has changed over time, when something was built, when boundaries changed and identify how the names of places have changed.

Context and provenance

Examining the context and provenance of a source is always important, but for maps it is particularly so. As maps are symbolic representations of a place we cannot interpret them effectively unless we understand who made them, when and why.

A map is an image of a place at a particular time, but it is nothing like a photograph. Reducing the details of a place to fit on a page means some features are omitted. The choice of what to include and what to omit depends on the purpose of the map.

The context of maps is spatial, chronological and cultural. Spatial, because a map represents just a portion of the earth and it helps to know where the map sits within the broader landscape. Chronological, because the map represents a place in time and without knowledge of which time the map is pretty useless. Cultural, because culture influences the purpose of the map, and the symbols and conventions used.

If you are lucky, the map itself may provide contextual information. Brighton le Sands subdivision, New South Wales Australia (State Library, New South Wales)

When exploring the context and provenance of a map, look for information about both the creator of the map and the publisher. Try to find the date that it was created and the date that it was published – these two dates could vary considerably. It is also important to consider whether the creator of the map had primary knowledge of the place or has based the map on other sources.

Analysing content

Why was the map created? What was the creator trying to achieve? This information will help you determine biases or intentional deceptions reflected in the map, and also help you interpret the symbols.

No maps contain details of every feature. They omit details and they simplify features. Be aware of this and consider the implications for any conclusions you are drawing from the map.

Mapping conventions exist and if they have been applied to the map they will assist your analysis. The title may help you identify the purpose, location and date. There may be a north arrow or compass rose to help you orientate, or if not, perhaps north is at the top of the map. If a scale is included, that will help you judge distances, however, not all maps contain scales. Even worse, maps may employ different scales in different parts of the map. Look for a legend or key to the symbols used. If there is none, examine similar maps and see if the legend on those maps help.

Subdivision plan, Brighton le Sands, New South Wales Australia. Scale altered to exaggerate proximity of the beach to the railway line (State Library, New South Wales)

Although it will be difficult to determine, try to find out the source of the data used to compile the map. Maps may be original or derivative sources. They may be produced by a surveyor based on their own research in the field, or derived from other maps, photos, drawings and descriptions.

Using maps

Maps can provide valuable information for your family history, such as the distance between two places. You will need to make a judgement call in each circumstance to determine whether a map is the best source to cite for that information. In some cases, additional sources will be needed, while in others, an old map may be the only evidence available.

Jamaica, 1763. This map is the only evidence I have of the location of land granted to my ancestor (Jamaican Family Search, provenance unknown)

More and more maps are being made available online. This is fantastic for family history, because digital images are often rich in content and the technology makes it easy to navigate around the map and zoom in on the features of interest.

Extracts of maps are a great way to illustrate your family history. Vast numbers of old maps are available with no copyright restrictions. When using newer maps, take care to examine both copyright and licensing restrictions that may apply.

Citing maps


Title and/or description (including location), date and/or edition, creator, repository

For online maps, you might add the URL


Parish of Arding, County of Sandon, 4th edn, Lands Department, 27 September 1926, Mitchell Library Parish Maps

Plan of the village of North Harbour, 1828, Thomas Mitchell, NSW State Library,

How and where to find them

The best places for maps depends on the location of the map you are searching for. However, you might like to try these websites:


FamilySearch wiki

Cyndi’s List, maps category

Genuki UK

A few other good sites

Library of Congress, US

David Rumsey Historical Maps Collection

Layers of London

Old Maps Online

National Library of Scotland

Your State and National Libraries, and archives. Look for guides, such as NSW State Archives

Want more?

This is no. 5 in my series about using sources. You can read the previous articles here: