The Consolidation of Task Knowledge for Lifelong Machine Learning

Lifelong Machine Learning (LML) considers situations in which a learner faces a series of tasks over a lifetime. An LML system requires a method of using prior knowledge to learn models for new tasks as efficiently and effectively as possible, and a method of retaining task knowledge after it has been learned. Knowledge retention is necessary for a lifelong learning system, however it is not sufficient. We propose that domain knowledge must be integrated for the purposes of efficient and effective retention and for more efficient and effective transfer during future learning. The process of integration we define as consolidation. The challenge for an LML system is consolidating the knowledge of a new task while maintaining and possibly improving knowledge of prior tasks; this requires a solution to the stability-plasticity problem. This paper provides a summary of prior work by the author on the consolidation problem within various LML systems.