https://phys.org/news/2018-07-alarming-error-common-survey-analyses.html

"In my consulting work for organizations and businesses, people would come in and say, 'Well, here's my estimate of how often something occurs in a population,' such as the rate of a disease or the preferences for a political party. And they'd want to know how to interpret that. I would respond, 'Have you accounted for weighting in the survey data you're using—or, did you account for the sample design?' And I would say, probably 90 percent of the time, they'd look at me and have no idea what I was talking about. They had never learned about the fundamental principles of working with survey data in their standard Intro to Stats classes."

As a survey methodologist, West wondered whether his experience was indicative of a systemic problem. There wasn't much in the academic literature to answer the question, so he and his colleagues, Joseph Sakshaug and Guy Aurelien, sampled 250 papers, reports and presentations—all available online, all conducting secondary analyses of survey data—to see if these analytic errors were, indeed, common.