Reliability is a source evaluation skill which asks you to draw a conclusion about the trustworthiness of a source.
In the same way that it is rare to get sources that are 100% accurate, it is hard to be completely sure that sources are 100% reliable. Therefore, when we talk about reliability of sources, we can talk in terms of ‘degrees of reliability':
Extremely - Very – Somewhat – Rarely – Not very
Based upon what you discovered in your analysis of the source, you can establish reliability based upon any of the following:
The source has been fact-checked, and subsequently approved, by its audience. (e.g. an academic journal)
When using information from sources to prove your own argument, you need to be able to use sources that are reliable. If you have found a source which you discover to be unreliable, the best advice would be not to use the source.
However, if the source is too relevant to your topic that you cannot use another, use a different evaluation skill to argue for why you are using it, rather than simply arguing that the source is unreliable.
Based upon what you discovered in your analysis of the source, you can establish its unreliability based upon any of the following:
The source has not been fact-checked by an educated audience. (e.g. it is a online blog post)
Demonstrating source reliability in your writing:
This source is mostly reliable regarding factory conditions in the Industrial Revolution because the creator lived next to a major industrial facility during the 19th century.
John Smith, whose own personal experience as a soldier in World War I provides a highly reliable description on the living conditions in the trenches, says “…” (1981, 31).
This official population survey was conducted by the Australian Bureau of Statistics which is responsible for providing the Australian government with ofﬁcial data. As a result, the information provided can be considered very reliable.
Demonstrating source unreliability in your writing:
Plutarch describes what happened, saying, “…”, but he often wrote to entertain so historians can’t always trust what he says (as found in Scott-Kilvert 1960, 76).
The information is drawn from a random website that does not provide information about the author, so it is probably a very unreliable source.