One of the key principles in family history is that we should aim to use original sources wherever possible. However, derivative sources have an important place in our research too, so we need to learn how to use them effectively.
An original source is the first version of a source. It is usually created close to the time of the events depicted in the source, but not always. A derivative source is a source created from an original source or from other derivative sources. It is usually created some time after the events depicted in the source, but again, not always. A national or state newspaper reporting on an event which had already been reported upon in the local paper, is an example of a derivative but contemporary source.
I like to categorise derivative sources as copies, transcriptions or compilations.
A copy may be a photocopy, photo or microfilm. It involves minimal changes to the source. A transcription is a written or printed copy, and changes are more likely to occur. A compilation is a derivative source that is based on more than one source, so it is least like the sources on which it was based. A family history book is an example of a compilation.
Of course, it is more complex than these three categories. Copies can be made from copies; transcriptions from copies; copies from transcriptions; extracts from compilations, and so on.
Derivative sources are often regarded as less desirable than original sources. This is because the process of derivation increases the chance of changes and errors in the information, and because the creator of a derivative source is less likely to have first-hand knowledge of the event or context of the event.
However, there are benefits in using derivative sources.
- They are generally more accessible than original sources.
- Technology, such as optical character recognition (OCR) and image enhancement, creates derivative sources that are more legible than the original sources.
- The creator of a derivative source may have access to new information or provide new perspectives on the information.
Analysing a derivative source
The approach to using derivative sources is similar to any other source. First you need to evaluate the source, then evaluate the information and then evaluate the evidence.
The two key differences when analysing derivative sources are:
- It is critical that you understand the nature of the source. Is it a copy, transcription or compilation? And, how far is it removed from the original – is it a copy of a copy of a copy? This information affects your analysis of the reliability of the source and the information it contains.
- It is also important to examine where each piece of information within the source came from. Derivative sources often contain information from a variety of informants or sources, which means that the quality and reliability of each piece of information will vary. Do not make the mistake of only evaluating the reliability of a derivative source as a whole.
For more guidance on analysing sources, click on the category ‘sources’ on the right side of this screen, or jump straight to these articles: