"People say" and "Everybody thinks" are expressions sometimes used to spread information not backed by fact. Reliable survey data can be found in these sources.
The CRAAP Test is a list of questions (developed at Meriam Library at California State University, Chico) to help you analyze the validity of a source. Here is a short list of things to look for to see if your information source passes the CRAAP test:
Here's the original: