This document summarizes the methodology of the 2017 Edelman Trust Barometer survey. It describes the different respondent populations surveyed (general online population, informed public, mass population) and sample sizes in 28 countries. Key findings show that trust has collapsed among the mass population in 20 of 28 countries compared to the informed public. Media trust is at an all-time low in 17 countries. Countries with high levels of societal fears like corruption and immigration combined with a belief that the system is failing are most prone to populist action. The U.S. is highlighted as a case where Trump voters expressed higher levels of fear compared to Clinton voters.