Machine learning systems are more advanced than they ever have been, but a critical component is still missing: machine common sense. Machine common sense is "the basic ability to perceive, understand, and judge things that are shared by nearly all people and can be reasonably expected of nearly all people without need for debate." DARPA believes that possessing this knowledge could significantly advance the relationship between humans and machines, but encoding this capability is a difficult task. "The absence of common sense prevents an intelligent system from understanding its world, communicating naturally with people, behaving reasonably in unforeseen situations, and learning from new experiences," said Dave Gunning, a program manager in DARPA's Information Innovation Office (I2O). "This absence is perhaps the most significant barrier between the narrowly focused AI applications we have today and the more general AI applications we would like to create in the future."