SIFT is a handy acronym that reminds you to analyze a source to make sure it is valid and reliable.
Stop: The source you found seems great. Stop to take a moment to evaluate it.
Investigate the source: This is exactly as it seems. For example, if you found an article, what journal published it? Does it have a reputation, or is it difficult to find information about it? What about the author(s)? Typically, you can find a trail of their productivity and credentials that indicate experise. Use lateral reading in which you search out opinions of other reputable sources to know what they think of your source.
Find better coverage: Evaluate the source you found further by finding and comparing other sources on the topic. As a researcher, it always helps to explore multiple viewpoints on a topic to get a sense of the scholarly conversation that is taking place. When you do this, even quickly, you may come across an even better source than you initially discovered.
Trace claims to the original context: For scholarly works, we can think of "tracing claims" as verifying that the authors' conclusions stem directly from their results. Scholarly articles will typically share their claim in an introduction section at the top, an analysis of a review, research methods, and results, and then offer a conclusion based on these sections.