The 2016 Arab Opinion Index is the fifth in a series of yearly public opinion surveys across the Arab world. The first survey was conducted in 2011, with following surveys in 2012/2013 and 2014. The 2016 Arab Opinion Index is based on face-to-face interviews conducted with 18,310 individual respondents in 12 separate Arab countries: Saudi Arabia, Kuwait, Iraq, Jordan, Palestine, Lebanon, Egypt, Sudan, Tunisia, Algeria, Morocco and Mauritania. Sampling followed a randomized, stratified, multi-stage, self-weighted clustered approach, giving an overall margin of error between +/- 2 % and 3% for the individual country samples. The overall samples guarantee probability-proportional-to-size (PPS), ensuring fairness in the representation of various population segments. With an aggregate sample size of 18,310 respondents (50% of whom were men and 50% women). The Arab Opinion Index remains the largest public opinion survey covering the Middle East and North Africa. The fieldwork was carried out by an overall team of 840 individuals (half of whom were women), who conducted 45,000 hours of face-to-face interviews, covering a total of 760,000 kilometers across the population clusters sampled.