People's attention spans are decreasing, so a survey that takes more than a couple minutes are less likely to be started or completed (Cunningham CT, Quan H, Hemmelgarn B, Noseworthy T, Beck CA, Dixon E, Samuel S, Ghali WA, Sykes LL, Jetté N. (2015) Exploring physician specialist response rates to web-based surveys. BMC Med Res Methodol. 9;15:32).