[notRobot]

Wikipedia is actually the secondary source when someone reads a page on it, and it requires primary sources (like factbooks) to cite to exist.

[Antibabelic]

This is incorrect. Wikipedia relies primarily on secondary sources, which makes it a tertiary source, and it describes itself this way.[1] The World Factbook does not collect the information it provides, making it a secondary source.

[1]: https://en.wikipedia.org/wiki/WP:PSTS

[FrustratedMonky]

It can be both. It uses Primary and Secondary sources. That is why you check the references and use them appropriately.

[Loughla]

The problem is who checks the sources. Of the what billions of sources, how many have actually been verified?

[Isamu]

>who checks the sources

I do, when I’m reading something and accuracy matters. Anybody who cares about accuracy will investigate the sources. I know people will complain that “nobody” does this, but it is essential, without checking sources you are just casually reading. That goes for books and all media consumption. If a book or any media (ahem Tucker) doesn’t give you enough information to be able to look something up, that is rather a red flag of obfuscation.

[lazide]

Also, when there are conflicts, who decides what the ‘facts’ are, eh?

is is the Gulf of America or not?

[tokai]

Encyclopedias are by definition tertiary sources.

[SanjayMehta]

Wikipedia does not allow primary sources.

[Antibabelic]

This is very much false, Primary sources only play a supporting role on Wikipedia, but they are definitely allowed. For example, if you're writing an article on Apple you can cite Apple for what Wikipedia calls "uncontroversial self-description". However, before that, you have to establish the notability of Apple through reliable secondary independent sources. The contents and focus of articles is also dictated by secondary sources. For example, if you take a controversial subject like Urbit, the article would have to reflect the priorities of (mostly critical) journalistic pieces on Urbit. You can cite its documentation for a technical description (that would be "uncontroversial self-description", as I mentioned before), but this would have to be a small part of the article, because it wouldn't reflect the focus of secondary sources.

[NetMageSCW]

Which is often stupid when the only people who know the truth are the people who were there. Hearsay from secondary sources is not an improvement in that case.

That’s why I used to like Quora - you would often see an answer provided by the primary (and only definitive) source for questions.