Finding information is just the first step. Next you need to evaluate what you find. This guide on evaluation discusses:
- General evaluation questions to ask about all information
- Evaluating popular news and websites
- Types of scholarly literature (including primary and secondary articles in the sciences, systematic reviews, meta-analyses, and grey literature)
- Peer review
- Reading science information
- Evaluating AV media
Although most peer-reviewed articles have been screened as a part of the publication process, not all articles are created equal. Determining the value of a particular paper or other resource is important.
The main criteria are:
- Quality & Accuracy: Quite simply, is it good science? Very few scientifically incorrect papers are published and papers with serious scientific errors tend to be noticed right away (that's the purpose of peer review and publication itself). It does happen however. Check for errata, debates in the letters and opinions section, and later research. Also, some papers are much more informative and thorough than others. Some researchers will try and "slice" their research into the smallest possible publishable findings so as to be able to generate multiple papers out of a single study. Others may have issues with their methodology.
- Authority: It can be risky to generalize, but authors with many publications in a given area are usually older, more experienced, and more knowledgeable about a given research area. In the author affiliation section or by doing a web search for the author, you can often find more information on their education and credentials in the subject area.
- Quantity of Citations: Papers that are cited more times are said to have had greater impact; other scientists found them more useful. Obviously this will vary for newer versus older papers, which is why you should also consider . . .
- Currency: Newer findings are generally (but not always) better than old ones. Science and engineering are in a constant process of revision and improvement. Old findings may be perfectly accurate and important, but later research will usually refine and expand upon it.
- Relevance: Don't rely just on keywords or the abstract--read the paper fully if you are trying to decide whether to use it.
- Limitations of the Search Engine/Database/Index: Never assume that you're "getting everything" when you use an individual database or search tool; there are always limits to coverage regarding subject area, age, international coverage, etc.
- Journal: Some journals are more prestigious than others, having broader readership and/or more-selective criteria for accepting papers. Publication in a journal like Science orNature usually marks a paper as being exceptionally important. One good way of determining the importance of a given journal is . . .
- Impact Factor: Web of Science, Scifinder and several other databases will all link you the 2-year Impact Factor for the journal of any article you look at: You won't have to calculate it yourself.
- Point of View or Bias: This can be difficult to determine at first glance but reading an article in comparison to others on the subject, checking the language used and whether the authors address alternate points of view in their literature review, and seeing if the authors disclose their funding sources (as they are required to do) can help.