Learning Flexible Concepts from Streams of Examples: FLORA 2

FLORA2 is a program for supervised learning of concepts that are subject to concept drift. The learning process is incremental in that the examples are processed one by one. A special feature of our program consists in keeping in memory a subset of examples { a window. In time, new examples are being added to the window while other ones are considered outdated and are forgotten. In order to track the concept drift, the system keeps in memory not only valid descriptions of the concepts as they are derived from the objects currently present in the window, but alsòcandidate descriptions' that may turn into valid descriptions in the future.