Understanding Family History Sources: A Guide to Source Types

Learn how to identify and evaluate different types of genealogical sources to strengthen your family history research.

Understanding what type of source you’re working with is crucial for genealogical research success. The type of source directly affects how accurate the information might be and how you should analyse it. This knowledge helps you reach stronger conclusions about your family history.

This post was originally published in November 2023 and last updated on 5 July 2025

Why Family History Source Types Matter

You learn about your ancestors by studying information in sources and using that information as evidence. The quality of your conclusions depends on your ability to analyse sources effectively.

Different source types have different strengths and weaknesses. Recognising these differences helps you:

• Evaluate information accuracy
• Identify potential errors or bias
• Plan your research strategy
• Corroborate findings across multiple sources.

Primary vs. Secondary Sources: The Traditional Approach

Historians traditionally categorise sources as primary or secondary:

Primary sources are created during the time period being investigated. Examples include birth certificates, marriage licenses, and contemporary diaries.

Secondary sources are created later and draw upon primary sources for information. Examples include published family histories and compiled genealogies.

Benefits of Each Source Type

Primary sources tend to provide more direct information because:

• Informants may have participated in the event
• Information is typically more accurate due to less copying
• Creators were alive during the event and had contemporary insights.

Secondary sources offer their own advantages:

• They may compile information from multiple sources
• Analysis and interpretation are often included
• They may correct primary source errors
• They help identify research leads and other sources
• They’re invaluable when primary sources are scarce.

A Better Classification System: Original vs. Derivative Sources

A more practical approach for genealogists uses the terms original and derivative sources:

Original sources are the first version of any source. They’re generally considered the most reliable because:

• They typically contain fewer errors
• They’re usually contemporary to the events
• Creators likely had firsthand knowledge or direct witness accounts.

Derivative sources are created based on information from other sources. While potentially less reliable due to the copying process, they can still be valuable when used appropriately.

This classification actually creates three types of sources:

1. Original sources (nearly always contemporary)
2. Derivative contemporary sources (created during the time period but based on other sources)
3. Derivative sources created later.

Four Categories of Derivative Sources

Understanding these categories helps you evaluate source reliability:

1. Images

Microfilm copies, digital scans, and photographs of original sources make minimal changes to content. While practically treated as original sources, be aware that:

• Copies may be incomplete
• Image order might have changed
• Multiple sources might be combined.

2. Transcriptions

These involve copying content with inevitable format changes. Consider:

• Who made the transcription (professional vs. amateur)
• When it was made (contemporary transcribers may make fewer errors due to knowledge of events)
• Purpose of the transcription.

3. Collections and Databases

Sources in collections should be treated as derivative because:

• Selection processes alter context
• Different source types might be combined
• Indexes and explanatory materials are often added
• Errors can occur during compilation.

4. Authored Works

These synthesise information and include the writer’s interpretations. Examples include:

• Family trees (with or without citations)
• Published family histories
• Research notes and abstracts.

Special Considerations

Documents of Record

Sources created by jurisdictions (churches, government agencies) are usually produced according to standards or legislation. Understanding these standards helps with interpretation.

DNA as a Source

DNA test results should be considered original sources, while everything generated from analysis (match lists, relationship predictions, cluster maps) are derivative sources.

Newspaper Articles

These demonstrate why classification isn’t always straightforward. While newspapers are typically called primary sources under the traditional categorisation system, individual articles might be:

• Based on firsthand reporter experience
• Compiled from other sources
• Written decades after the event.

Best Practices for Source Analysis

1. Use multiple source types to maximise information and identify inconsistencies
2. Don’t over-generalise – each source requires individual evaluation
3. Consider the creator’s perspective and potential biases
4. Understand the source’s purpose and intended audience
5. Look for corroborating evidence across different source types.

Conclusion

No single source type is inherently better than another. Each has strengths and limitations. The key is understanding these characteristics and using them appropriately in your research.

Remember that contemporary sources provide period insights, while later sources might offer different perspectives that weren’t clear to original participants. A skilled genealogist combines multiple source types to build the most complete and accurate family history possible.

Understanding source types is fundamental to genealogical analysis. This knowledge helps you evaluate information critically, identify potential issues, and make informed decisions about your research conclusions.

Continue developing your source analysis skills by exploring the detailed methodologies in genealogical research guides and considering formal genealogical education programs.

More information

For more of my articles on improving your search techniques, go to the Research page.

For more articles about analysing sources, go to the Analyse page.

About the Author

Danielle Lautrec is a genealogy educator, researcher, and author of The Good Genealogist. With qualifications in history, family history, and historical archaeology, she teaches for the Society of Australian Genealogists.