SAT阅读素材:a learning sysstem

　　Learning, Rule, Environment and overall planning of a learning sysstem

　　The task of learning from environment should be specified. It requires the learner to infer the laws of the environment in terms of its percepts and actions, and use the laws to solve problems .

　　Based on research on problem space creation and discrimination learning, first design an approach in which exploration, rule creation and rule learning are coordinated in a single　framework. With this approach, the system Nell creates certain rules by noticing the　changes in the environment when actions are taken, and later refines the rules by explaining the failures of their predictions. Unlike　many other learning systems, nell treats learning and problem solving as interleaved activities, no training instance nor any concept hierarchy is necessary to start learning. Furthermore,　the approach is capable of discovering hidden features from the environment when normal discrimination process fails to make any progress.