Moral Machine[24] is an online platform that generates ethical dilemma scenarios faced by hypothetical autonomous machines, allowing visitors to assess the scenarios and vote on the most morally acceptable between two unavoidable harm outcomes. The presented scenarios are often variations of the trolley problem.[25][26][27] As of December 2017, the platform has collected 40 million decisions from millions of visitors from 233 countries and territories. Analysis of the data showed broad differences in relative preferences among different countries, and correlations between these preferences and various national metrics.[28]