Why survey estimates of the number of Americans online don’t always agree

How many US adults use the internet? There is a lot of information available from large, high response rate federal surveys as well as from surveys conducted by Pew Research Center and other organizations. However, these different sources of information measure internet use in ways that can be tricky to reconcile. Depending on the source, the estimated share of Americans who were online as of 2017 and 2018 is as low as 79% or as high as 89%. While Pew's approach has evolved over time, the current measurement consists of two questions: “Do you use the internet or email, at least occasionally?” and “Do you access the internet on a cellphone, tablet or other mobile handheld device, at least occasionally?”