Book excerpt: The World Justice Project (WJP) joins efforts to produce reliable data on rule of law through the WJP Rule of Law Index 2016, the sixth report in an annual series, which measures rule of law based on the experiences and perceptions of the general public and in-country experts worldwide. We hope this annual publication, anchored in actual experiences, will help identify strengths and weaknesses in each country under review and encourage policy choices that strengthen the rule of law. The WJP Rule of Law Index 2016 presents a portrait of the rule of law in each country by providing scores and rankings organized around eights factors: constraints on government powers, absence of corruption, open government, fundamental rights, order and security, regulatory enforcement, civil justice, and criminal justice. A ninth factor, informal justice, is measured but not included in aggregated scores and rankings. These factors are intended to reflect how people experience rule of law in everyday life. The country scores and rankings for the WJP Rule of Law Index 2016 are derived from more than 110,000 households and 2,700 expert surveys in 113 countries and jurisdictions. The Index is the world%s most comprehensive data set of its kind and the only to rely solely on primary data, measuring a nation%s adherence to the rule of law from the perspective of how ordinary people experience it. These features make the Index a powerful tool that can help identify strengths and weaknesses in each country, and help to inform policy debates, both within and across countries, that advance the rule of law.