The rule of law has been considered as one of the key dimensions that determine the quality and good governance of a country. Research, like the Worldwide Governance Indicators, defines the rule of law as: "the extent to which agents have confidence and abide by the rules of society, and in particular the quality of contract enforcement, the police and the courts, as well as the likelihood of crime or violence." Based on this definition the Worldwide Governance Indicators project has developed aggregate measurements for the rule of law in more than 200 countries, as seen in the map below. A government based on the rule of law can be called a "nomocracy", from the Greek nomos (law) and kratos (power or rule).