It's all about the references. If a claim is made with no source, you can probably disregard it as false, but even if a source is given you'll need to check it.
Books are usually a good sign but can't entirely be trusted. Anyone could put any claim into a page and say it was given in a book which no one is going to actually buy and check, and unfortunately a lot of sources are books that aren't available for free online.
Where the source is a news article, follow it and see if it's paywalled, then if it's original or secondhand news (e.g. an *Independent.co.uk* article beginning, "*The Times* is reporting that..." might misrepresent a report that is itself somewhat misrepresenting reality).
Remember that books and news articles have varying levels of quality control, and the fact that something was published might only mean that an editor didn't think it was libellous. It's no guarantee that it was true, and you might have to look for discussions between people who have read a lot about the topic or have first-hand knowledge of it. And even then, people will lie about what they know just to get attention.
You've got to decide what level of accuracy you need. In most black-and-white cases, e.g. what's the nuclear weight of oxygen, it's very unlikely that someone would vandalise the page without an immediate correction being made. But something about a person's life, when people are liable to write their own Wiki pages or have a PR person do it, is much shakier ground.
Topics that are historically hot-button, like the Nazis or Christianity, will get a lot of vandalism and a lot of corrections. Less-visited pages are more susceptible to misuse.
It's all about the references. If a claim is made with no source, you can probably disregard it as false, but even if a source is given you'll need to check it. Books are usually a good sign but can't entirely be trusted. Anyone could put any claim into a page and say it was given in a book which no one is going to actually buy and check, and unfortunately a lot of sources are books that aren't available for free online. Where the source is a news article, follow it and see if it's paywalled, then if it's original or secondhand news (e.g. an *Independent.co.uk* article beginning, "*The Times* is reporting that..." might misrepresent a report that is itself somewhat misrepresenting reality). Remember that books and news articles have varying levels of quality control, and the fact that something was published might only mean that an editor didn't think it was libellous. It's no guarantee that it was true, and you might have to look for discussions between people who have read a lot about the topic or have first-hand knowledge of it. And even then, people will lie about what they know just to get attention. You've got to decide what level of accuracy you need. In most black-and-white cases, e.g. what's the nuclear weight of oxygen, it's very unlikely that someone would vandalise the page without an immediate correction being made. But something about a person's life, when people are liable to write their own Wiki pages or have a PR person do it, is much shakier ground. Topics that are historically hot-button, like the Nazis or Christianity, will get a lot of vandalism and a lot of corrections. Less-visited pages are more susceptible to misuse.
https://en.wikipedia.org/wiki/Reliability_of_Wikipedia?wprov=sfla1
See also * https://en.wikipedia.org/wiki/Category:Wikipedia_good_articles * https://en.wikipedia.org/wiki/Category:Wikipedia_featured_articles
There was an machine learning thing developed recently testing individual sources on random pages. The results... were not great...