It’s 2013. The Harlem Shake is on the radio and e-cigarettes are becoming a thing. A group of researchers convene to discuss these and other products containing nicotine.

In a 2014 paper detailing the outcomes of that meeting, the authors rated “electronic nicotine delivery systems” (e-cigarettes) as having “only 4%” of the maximum relative harm of cigarettes.

Critically, the authors stated their “understanding of the potential hazards” of e-cigarettes was “at a very early stage” because they lacked “hard evidence for the harms of most products on most of the criteria” they examined.

In other words, they noted their work was methodologically weak and their estimates were just that — guesses based on their opinions rather than scientific evidence.