In general, for all formats:
- Does your assignment include stipulations about how old your sources can be? Use database limiters or sorting tools to include appropriate publication dates. Remember: some older materials still may be helpful in establishing background information, even if you do not use the older sources in your final product.
- Check the publication date. Have events occurred since the publication that require additional research?
- Is the source a classic or core work in the field? If so, the publication date may not matter.
- Look for the copyright date. A reprint date should not be considered because the information has been reprinted, not updated.
- Consider the publication cycle and how long it takes for books to be published. Examine the resources cited in the book and determine the age of the information and statistics that are included in the book.
- Perform a title search in the library's catalog for the book. Is there a newer edition of the book than the edition you're using?
- If the book is older, does it offer historical context that would still be useful or add value to your research?
For periodical articles:
- When was the article published?
- Is the article from a daily newspapers, weekly magazine, monthly publication or journal? Consider the publication cycle and how long it takes for scholarly / peer-reviewed articles to be published. How old are the information and statistics included in the article?
- If the article is older, does it offer some value to your research? Does it reveal details of a specific time or place that help fill in gaps in your research?
- Can you determine when the information was created or last updated? (Don't be fooled by automatic date tickers!)
- Are there any “dead” links on the page?
- Are there references to events that can help determine when it was last updated?