Information comes in various "packages" (or publication types):
Different publication types have different characteristics. These give us clues to the credibility of the information they contain.
One publication type, the Scholarly journal, has a well known quality control system, known as the peer review process.
What is peer review?
Expert researchers in an academic discipline, such as medicine or sociology, report their research findings in scholarly journals. Over time, the articles published in a journal form a serious written conversation among the experts. To ensure quality, many scholarly journals require peer review of articles before they are published. A peer reviewer is simply another expert in the same academic field or discipline as the author. Prior to publication, the reviewer looks at the article's significance, method, and possible bias. Articles that don't meet the standards are not published. Many articles are published only after revisions. This "hurdle" is a form of quality control that we all benefit from.
At well-known journals, many authors compete for a limited number of publication slots, and this also serves to increase quality.
Now, try the questions.
Tips for web pages
Authors are primarily responsible for their claims, but the groups that publish (or sponsor) a web site are also involved. Their reputations may depend on the quality of what is published. Publishers who value their reputations have a lot to lose, so they may provide some quality control.
The following four domains are restricted to certain kinds of institutions. This can be reassuring, because we know who we are dealing with.
Other domains can be used by anyone. People buy domains for their own web sites.
Remember, the original author is ultimately responsible for the claims. At the same time, the author who is citing the original work of others has responsibility for evaluating its credibility.
Sometimes a site will republish an article from another publication.
Can you answer yes to all these? If so, then you probably have a credible source for your claim!
That doesn't guarantee that they claim is correct. Mistakes happen all the time. But you are justified in believing so.