I'm conducting an anonymous quantitative survey on SurveyMonkey and some participants left the majority of the questions unanswered. How can we encourage participants to completely answer all questions in the survey?
Did you do pilot testing before running the main survey? Many a time respondents find questions offending/ response anchors not appropriate etc. The demographics of people who left the survey mid way, may provide you some insight as why some kind of people are not responding to some specific questions.