Reason No. 3. To acknowledge the work of others
If we use the work or ideas of another person in our family history research then we need to acknowledge their work, and source citations are a good way to do that.
If you present the work or ideas of others in a way that suggests that it is your own work then you are committing plagiarism. Failing to acknowledge the work of others is not a big deal if you do not present the results of your research to others. However, you do need to cite your sources if you put your research online, or include it in a book, essay, thesis or journal article. A source citation is needed when you quote from another work; include ideas or the work of another researcher; or if you include data, images or media produced by someone else.
Just because someone has researched the same family as you, it does not always mean that you have to acknowledge their research. If you extract information from their research, then verify it using original or reliable derivative sources, then it is those sources that you cite, not their research. This is because the information is not their creative property. However, if they wrote a story about their family based on the information, then that story is their creative property and needs to be acknowledged with a source citation. In such cases, copyright may also apply and you may need to seek their permission to reproduce it.
Reason No. 4. To help you analyse the source
One of the most important and often overlooked reasons to cite your sources is that doing so helps you analyse the source, and this improves the quality of your research.
Writing a source citation forces you to examine the source more closely. You have to consider the nature of the source and why it was created. You have to identify who created the source and where it was created. You also have to identify if there is anyone with creative property rights – such as an author or a photographer. And, if it is an unpublished source, you also have to think carefully about the details required to help someone find the source for themselves.
All of the information gathered for the purpose of citing a source helps us to understand the information in the source and increases the likelihood that we will interpret the source and the information accurately.
[The image used here is believed to be in the Public Domain, but a citation won’t hurt: Harrison Fisher, Fair Americans, New York, Charles Scribner’s Sons, 1911]