It is important to realize that sources on the World Wide Web are frequently not authoritative references. There is a lot of misinformation on the Web, since no editor or publisher oversees it, as is the case with books. "Facts" are often simply wrong; opinions, hearsay, and "folk beliefs" are stated as facts; and sources are often omitted.
Regarding our subject matter, the Web seems in particular to have a lot of false etymologies on it. For etymologies in particular, then, you had better get your information from books and other published sources, or at least check any putative etymologies you find on the Web with authoritative published sources like dictionaries or other books.
More generally, you have to use judgment as to what is an academically viable source. Personal homepages of non-professionals (on the relevant topic) are not a good bet.
Further, when a website makes specific reference to published sources, that helps bolster the level of confidence in the information posted. If no reference is given to information that is presented as factual in a web document, then the information should not be considered reliable without checking.
Use only information which you can check (e.g. an etymology can be checked in a dictionary) or which has a stated published source. In your references, you should give the website from which you got the information, and include in the same reference the published source given at the website. Even if you don't check the published source yourself, you have at least given your reader a way to go and check the information for accuracy--a must for any serious academic work.
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© Suzanne Kemmer
Last modified August 2017