The Washington Post published a long article about a public opinion survey of North Koreans: here are the details

"The NGO surveyed 20 men and 16 women between the ages of 28 and 80." I am not making this up.  This is at the level of Thomas Friedman when he generalizes about public opinion on the basis of his conversations (from hotel to airport or vice versa) with cab drivers in various cities he visits.