What kind of source it is
Wikipedia is a free online encyclopedia written and edited by volunteers. Anyone can propose changes, and a community of editors reviews them according to published policies, including that statements should be verifiable and that articles should reflect what reliable published sources say. That model produces a vast amount of useful material, and also uneven quality.
Because the content is always changing, any given page is a snapshot. A well-maintained article on a popular topic may be accurate and thoroughly sourced. An obscure article may be thin, outdated or poorly referenced. Articles on contested or political subjects can be subject to disputes. Judging the specific page in front of you is more useful than a blanket verdict on the site.
Why it is a good starting point
Used as a first step, it does several things well:
- It gives you an overview of a topic and the vocabulary used in the field, which helps you search more effectively later.
- It points to related subjects and key names, dates and terms.
- It usually collects references to books, articles and reports you can follow.
These benefits are much like those of any general reference work. The main limitation is that you should not stop there. For schoolwork and academic writing, instructors commonly expect you to cite the original sources rather than an encyclopedia, whether it is a print one or an online one. Check what your own course or institution requires.
Read the article critically
Look at the opening and the structure. Does the article have a clear summary, sections that cover different aspects, and a balance of viewpoints where they exist? Banners at the top sometimes warn of problems, such as a lack of sources, a possible bias, or content that is disputed. Take these seriously.
Check the references. A well-supported article has many inline citations to reliable sources. Notice how many claims have none. Look for the label “citation needed,” which editors add when a statement lacks a source. A section with sparse references deserves more caution.
Evaluate the cited sources themselves. A footnote proves only that someone wrote a source down, not that the source is good. Are the references to books from established publishers, journals, official records or reputable news reporting? Or to personal blogs and promotional pages? The same questions in source evaluation apply to the footnotes.
Use the tabs that most readers skip
Each article has more than the main text.
Talk page. This is where editors discuss the content: disagreements, proposed changes, arguments about what counts as a reliable source. A long and heated talk page is a sign that the topic is contested, which is useful to know before you rely on the article.
View history. The edit history lists every change, with dates and short summaries. You can see how recently the page was updated, whether it is stable or frequently changed, and whether large chunks have been added or removed recently. If you spot a sudden change to a surprising claim, that is a reason to look more closely. You can also compare any two versions to see exactly what was changed.
These tools give you a sense of how settled the page is. A topic with frequent reverts and arguments is a place to be especially careful, and you may want to consult other references on it.
Follow the references to the originals
The most valuable step is to leave the page. Click through to the cited source and read it. Check whether it actually says what the article claims. Sometimes a summary is slightly off, a source has been misread, or a link no longer works. When a link is dead, search for the title elsewhere, or look for an archived copy. If you cannot find the original, treat the claim as unverified.
Then cite the original. In your own work, name the books, papers or reports you actually consulted, not the encyclopedia page that led you to them. If you did use the encyclopedia for a general statement and your guidelines permit it, cite the specific page version and date you accessed, since the content can change. The rules vary by style, and the differences are explained in citation styles, while the principle of crediting what you used is part of avoiding plagiarism.
Cross-check with other sources
Compare what you find with at least one or two independent sources: a textbook, a specialized reference work, an official body or a library database. Differences are worth investigating. Where several good sources agree, you can have more confidence. Where they differ, the differences can themselves be part of what you report. Librarians can help point you to suitable specialist references.
If you want to understand who runs or funds a site that an article cites, the method of lateral reading works here too.
Cautions about using any single summary
- Articles may reflect the viewpoints and interests of the editors who maintain them, and some topics have more editors than others. Coverage can be uneven.
- Recent events change quickly, and early versions of a page can contain errors that are later fixed.
- Vandalism happens, and while it is often reverted quickly, you can still catch a page at a bad moment.
- Do not treat a confident tone as a sign of accuracy. This is true of any source.
A simple routine
- Read the lead and skim the headings to get oriented.
- Note the key terms, names and dates.
- Open the references and read a few of the most important cited sources.
- Check the talk page and view history for signs of dispute or instability.
- Search for independent sources and compare.
- Cite the sources you used, not the page that pointed you to them.
Used this way, an online encyclopedia is a helpful map. It is not the territory, and the best research uses it to find the routes to better sources.