User:Rollinginhisgrave/How I understand reliable sources

Every claim on Wikipedia should have a published source that directly supports it; that is, a source that makes the same claim. Sources contain many claims, some true, some less true; we want the former and we don't want the latter. How can we trust that a source's claim is correct?

To trust a claim, it needs to be well founded: based on good reasoning and good evidence. To assess if you can trust a source's claim, you take three steps:

1. The first, most important, is that you read the source and you read other sources talking about the subject. Then you ask: "Based on this source and other sources, do I believe this claim is true?" Don't think about any Wikipedia guidelines yet, just look to your gut. Ask yourself why you believe it. Is this something someone would lie about? Does it appear that the author published this based on good evidence? Does the author have the expertise to know this? Is this contradicting other sources?
2. The second is to look at things you may not have considered. We have compiled a list of important considerations at Wikipedia:Reliable sources, for instance: AGEMATTERS: could this claim be outdated? QUESTIONABLE: did this have a second, independent pair of eyes checking over this before it was published? If not, does this make you not believe it is true anymore?
3. The third is to doubt yourself. Ask yourself if your reasoning is sensible and convincing. Ask yourself if the author knows something you don't know. What looks contradictory to you may be perfectly coherent. What looks sensible to you may be incorrect. Err on the side of doubt, using common sense. Remember that just as claims must be verifiable, so must your reliability assessment. You need to be able to demonstrate why it's trustworthy, and your claim should be well-founded.

After asking these questions, you will have an opinion on the claim's truth. It will rarely be yes or no, rather it will fall somewhere between unbelievable and very well-founded. Where different editors will draw the line to call something trustworthy will vary, but the lower threshold for putting a claim in wikivoice is that you believe it is "probably true". Higher-stakes material (contentious claims about a living person, politics or medicine for instance) needs to meet a higher threshold.

When a claim falls a bit below the threshold into "may be true", we can attribute it. This is particularly good when two sources are both making well-founded claims that contradict each other. We don't know which is true, and it's not our job to figure it out. A claim that falls further is not sufficiently reliable to merit inclusion.

Note that a sources don't just make explicit claims. If we have a source saying "I did not kill my girlfriend", the author is explicitly claiming he didn't kill his girlfriend. But the source is also implicitly making claims: that the author is denying claims to the contrary, that the man had a girlfriend, even that there is a man. This usually manifests in a distinction between claims that, for instance, the world is flat, and a claim that the Flat Earth Society says the world is flat. We should assess the trustworthiness of each claim.

The above applies just as much to subjective claims of views, opinions and analysis, as we want to summarise such claims when they are well founded: based on good reasoning and good evidence.

As this process involves making a judgement, naturally, others may disagree. They may have different considerations and counter-considerations, or they may weigh the same ones differently against each other. Ultimately, the determination of whether a claim is well founded is decided by Wikipedia's consensus processes.